See tutors' answers!

Algebra ->  Tutoring on algebra.com -> See tutors' answers!      Log On


   
By Tutor
 | By Problem Number | 

Tutor:
New! Get regular updates about newly solved problems via algebra.com's RSS system.

Recent problems solved by 'josmiceli'

josmiceli answered: 9658 problems
Jump to solutions: 0..29 , 30..59 , 60..89 , 90..119 , 120..149 , 150..179 , 180..209 , 210..239 , 240..269 , 270..299 , 300..329 , 330..359 , 360..389 , 390..419 , 420..449 , 450..479 , 480..509 , 510..539 , 540..569 , 570..599 , 600..629 , 630..659 , 660..689 , 690..719 , 720..749 , 750..779 , 780..809 , 810..839 , 840..869 , 870..899 , 900..929 , 930..959 , 960..989 , 990..1019 , 1020..1049 , 1050..1079 , 1080..1109 , 1110..1139 , 1140..1169 , 1170..1199 , 1200..1229 , 1230..1259 , 1260..1289 , 1290..1319 , 1320..1349 , 1350..1379 , 1380..1409 , 1410..1439 , 1440..1469 , 1470..1499 , 1500..1529 , 1530..1559 , 1560..1589 , 1590..1619 , 1620..1649 , 1650..1679 , 1680..1709 , 1710..1739 , 1740..1769 , 1770..1799 , 1800..1829 , 1830..1859 , 1860..1889 , 1890..1919 , 1920..1949 , 1950..1979 , 1980..2009 , 2010..2039 , 2040..2069 , 2070..2099 , 2100..2129 , 2130..2159 , 2160..2189 , 2190..2219 , 2220..2249 , 2250..2279 , 2280..2309 , 2310..2339 , 2340..2369 , 2370..2399 , 2400..2429 , 2430..2459 , 2460..2489 , 2490..2519 , 2520..2549 , 2550..2579 , 2580..2609 , 2610..2639 , 2640..2669 , 2670..2699 , 2700..2729 , 2730..2759 , 2760..2789 , 2790..2819 , 2820..2849 , 2850..2879 , 2880..2909 , 2910..2939 , 2940..2969 , 2970..2999 , 3000..3029 , 3030..3059 , 3060..3089 , 3090..3119 , 3120..3149 , 3150..3179 , 3180..3209 , 3210..3239 , 3240..3269 , 3270..3299 , 3300..3329 , 3330..3359 , 3360..3389 , 3390..3419 , 3420..3449 , 3450..3479 , 3480..3509 , 3510..3539 , 3540..3569 , 3570..3599 , 3600..3629 , 3630..3659 , 3660..3689 , 3690..3719 , 3720..3749 , 3750..3779 , 3780..3809 , 3810..3839 , 3840..3869 , 3870..3899 , 3900..3929 , 3930..3959 , 3960..3989 , 3990..4019 , 4020..4049 , 4050..4079 , 4080..4109 , 4110..4139 , 4140..4169 , 4170..4199 , 4200..4229 , 4230..4259 , 4260..4289 , 4290..4319 , 4320..4349 , 4350..4379 , 4380..4409 , 4410..4439 , 4440..4469 , 4470..4499 , 4500..4529 , 4530..4559 , 4560..4589 , 4590..4619 , 4620..4649 , 4650..4679 , 4680..4709 , 4710..4739 , 4740..4769 , 4770..4799 , 4800..4829 , 4830..4859 , 4860..4889 , 4890..4919 , 4920..4949 , 4950..4979 , 4980..5009 , 5010..5039 , 5040..5069 , 5070..5099 , 5100..5129 , 5130..5159 , 5160..5189 , 5190..5219 , 5220..5249 , 5250..5279 , 5280..5309 , 5310..5339 , 5340..5369 , 5370..5399 , 5400..5429 , 5430..5459 , 5460..5489 , 5490..5519 , 5520..5549 , 5550..5579 , 5580..5609 , 5610..5639 , 5640..5669 , 5670..5699 , 5700..5729 , 5730..5759 , 5760..5789 , 5790..5819 , 5820..5849 , 5850..5879 , 5880..5909 , 5910..5939 , 5940..5969 , 5970..5999 , 6000..6029 , 6030..6059 , 6060..6089 , 6090..6119 , 6120..6149 , 6150..6179 , 6180..6209 , 6210..6239 , 6240..6269 , 6270..6299 , 6300..6329 , 6330..6359 , 6360..6389 , 6390..6419 , 6420..6449 , 6450..6479 , 6480..6509 , 6510..6539 , 6540..6569 , 6570..6599 , 6600..6629 , 6630..6659 , 6660..6689 , 6690..6719 , 6720..6749 , 6750..6779 , 6780..6809 , 6810..6839 , 6840..6869 , 6870..6899 , 6900..6929 , 6930..6959 , 6960..6989 , 6990..7019 , 7020..7049 , 7050..7079 , 7080..7109 , 7110..7139 , 7140..7169 , 7170..7199 , 7200..7229 , 7230..7259 , 7260..7289 , 7290..7319 , 7320..7349 , 7350..7379 , 7380..7409 , 7410..7439 , 7440..7469 , 7470..7499 , 7500..7529 , 7530..7559 , 7560..7589 , 7590..7619 , 7620..7649 , 7650..7679 , 7680..7709 , 7710..7739 , 7740..7769 , 7770..7799 , 7800..7829 , 7830..7859 , 7860..7889 , 7890..7919 , 7920..7949 , 7950..7979 , 7980..8009 , 8010..8039 , 8040..8069 , 8070..8099 , 8100..8129 , 8130..8159 , 8160..8189 , 8190..8219 , 8220..8249 , 8250..8279 , 8280..8309 , 8310..8339 , 8340..8369 , 8370..8399 , 8400..8429 , 8430..8459 , 8460..8489 , 8490..8519 , 8520..8549 , 8550..8579 , 8580..8609 , 8610..8639 , 8640..8669 , 8670..8699 , 8700..8729 , 8730..8759 , 8760..8789 , 8790..8819 , 8820..8849 , 8850..8879 , 8880..8909 , 8910..8939 , 8940..8969 , 8970..8999 , 9000..9029 , 9030..9059 , 9060..9089 , 9090..9119 , 9120..9149 , 9150..9179 , 9180..9209 , 9210..9239 , 9240..9269 , 9270..9299 , 9300..9329 , 9330..9359 , 9360..9389 , 9390..9419 , 9420..9449 , 9450..9479 , 9480..9509 , 9510..9539 , 9540..9569 , 9570..9599 , 9600..9629 , 9630..9659, >>Next

Linear-equations/534332: Hi! I need help in the following questions, it's only two. Please help and explain how and why you got what you got.
Directions: Write an equation for the line that is perpendicular to the given line and that passes through the given point.
1. (-1,-4); y= 1/6x+1
2. (-5,5); y= -5x+9
Please help, I know how to do it but when they twist it up like this i really don't get it. Please show all of the work and steps involved, and why. Thanks!
1 solutions

Answer 351467 by josmiceli(9661) About Me  on 2011-11-19 19:29:25 (Show Source):
You can put this solution on YOUR website!
(1)
(-1,-4)
+y+=+%281%2F6%29%2Ax+%2B+1+
This is in the form +y+=+m%2Ax+%2B+b+, where +m+ = slope
ANY line perpendicular to this line
will have slope = +-+1%2Fm+
Your equation has +m+=+1%2F6+, so any line
perpendicular to it has slope = +-+%281%2F%281%2F6%29%29+=+-6+
----------------
So far you have +y+=+-6x+%2B+b+. To find b, plug in
(x,y) = (-1,-4)
+-4+=+-6%2A%28-1%29+%2B+b+
+-4+=+6+%2B+b+
+b+=+-4+-+6+
+b+=+-10+
The equation of the perpendicular line is +y+=+-6x+-+10+
-----------------
(2)
(-5,5)
+y+=+-5x+%2B+9+
Slope of any perpendicular line = +-%281%2F%28-5%29%29+=+1%2F5+
Now plug in (x,y) = (-5,5)
+5+=+%281%2F5%29%2A%28-5%29+%2B+b+
+5+=+-1+%2B+b+
+b+=+6+
The equation is +y+=+%281%2F5%29%2Ax+%2B+6+
Here's a plot of these 2 lines:
+graph%28+400%2C+400%2C+-12%2C+12%2C+-12%2C+12%2C+-5x+%2B+9%2C+%281%2F5%29%2Ax+%2B+6%29+


Age_Word_Problems/534322: in 7 years daniell will be twice as old as she was 8 years ago. how old is she now?
1 solutions

Answer 351449 by josmiceli(9661) About Me  on 2011-11-19 17:16:52 (Show Source):
You can put this solution on YOUR website!
Let a = her age now
+a+%2B+7+ = her age in +7+ years
+a+-+8+ = her age 8 years ago
--------
given:
+a+%2B+7+=+2%2A%28+a+-+8+%29+
+a+%2B+7+=+2a+-+16+
+a+=+23+
She is 23 now


Travel_Word_Problems/534314: Lauren is jogging to the store at 10 mph. She gets what she needs and returns home at 5 mph. Her total jogging time was one hour. How far is the store from her house?

I need an equation...I don't understand how to do this...
1 solutions

Answer 351446 by josmiceli(9661) About Me  on 2011-11-19 17:11:29 (Show Source):
You can put this solution on YOUR website!
Let +d+%7D%7D%5D+=+distance+from+store+to+house+in+miles%0D%0ALet+%7B%7B%7B+t+ = time to go from house to store in hrs
+1+-+t+ = time to go from store to house in hrs
--------
House to store:
(1) +d+=+10t+
Store to house:
(2) +d+=+5%2A%28+1+-+t+%29+
---------------
Substitute (1) into (2)
(2) +10t+=+5%2A%28+1+-+t+%29+
(2) +10t+=+5+-+5t+
(2) +15t+=+5+
(2) +t+=+5%2F15+
(2) +t+=+1%2F3+ hr
and, from (1):
(1) +d+=+10t+
(1) +d+=+10%2F3+
The distance from store to house is 3.333 mi
check:
(2) +d+=+5%2A%28+1+-+t+%29+
(2) +10%2F3+=+5%2A%282%2F3%29+
(2) +10%2F3+=+10%2F3+
and
(1) +d+=+10t+
(1) +10%2F3+=+10%2A%281%2F3%29+
(1) +10%2F3+=+10%2F3+
OK


Distributive-associative-commutative-properties/534045: Two bike riders ride around a circular path, the first rider completes one round in 10 minutes and the second rider completes it in 12 minutes. If they both start at the same place and at the same time and go in the same direction, after how many minutes will they meet again at the starting place?
1 solutions

Answer 351241 by josmiceli(9661) About Me  on 2011-11-18 19:55:42 (Show Source):
You can put this solution on YOUR website!
The 1st rider will be back at the start every
10 minutes, that is 10 min, 20 min, 30 min, etc.
The 2nd rider arrives at start 2 minutes later
each times around. The 5th time around, rider
#2 is behind 10 minutes.
#2 has gone 5 times around in 12*5 = 60 min
In 60 min, rider #1 has gone 6 times around,
and they meet at start
The answer is 60 min or 1 hr


Travel_Word_Problems/534040: Two planes, which are 1790 mile apart, fly towards each other. Their speed differs by 45 mph. If they pass each other in 2 hours, what are their speeds?
1 solutions

Answer 351239 by josmiceli(9661) About Me  on 2011-11-18 19:44:53 (Show Source):
You can put this solution on YOUR website!
They approach each other at the sum
of their speeds.
I'll call the slower plane's speed +s+ mi/hr
The faster plane's speed is +s+%2B+45+ mi/hr
They pass each other in 2 hrs, so the sum
of their speeds is +1790+%2F+2+=+895+ mi/hr
---------------
+s+%2B+s+%2B+45+=+895+
+2s+=+895+-+45+
+2s+=+850+
+s+=+425+
+s+%2B+45+=+470+
Their speeds are 425 mi/hr and 470 mi/hr
Check answer:
Slower plane:
+d+=+425%2A2+
+d+=+850+ mi
Faster plane:
+d+=+470%2A2+
+d+=+940+ mi
+850+%2B+940+=+1790+
Correct


Probability-and-statistics/534042: The license plates in your state consists of 3 numbers followed by 3 letters. How many ways can you get the number 18 with no digits in between and with your first and last initial appearing consecutively in order?
1 solutions

Answer 351238 by josmiceli(9661) About Me  on 2011-11-18 19:35:00 (Show Source):
You can put this solution on YOUR website!
If I understand it right, there are only 2 ways to get
an 18. The 3 numbers can be
1 8 x
x18
----------
Suppose my initials are J M. I can have:
J M x
x J M
which is 2 possible ways
That means there are only +2%2A2+=+4+
different ways these can happen.


Age_Word_Problems/533974: 1. The present ages of Lewis and Brown are in the ratio 1:2. Three years from now, the ages will be in the ratio 3:5. Find the present ages of Lewis and Brown.

2. The ages of Ashley and Mary are in the ratio 4:7. The sum of their ages is 22. Find the ages of Ashley and Mary.
1 solutions

Answer 351226 by josmiceli(9661) About Me  on 2011-11-18 17:40:54 (Show Source):
You can put this solution on YOUR website!
Let a = Lewis's age now
Let b = Brown's age now
given:
(1) +a%2Fb+=+1%2F2+
(2) +%28+a+%2B+3+%29+%2F+%28+b+%2B+3+%29+=+3%2F5+
------------------------
(2) ++a+%2B+3+=+%283%2F5%29%2A%28+b+%2B+3+%29+
(2) +5a+%2B+15+=+3%2A%28+b+%2B+3+%29+
(2) +5a+%2B+15+=+3b+%2B+9+
(2) +3b+-+5a+=+6+
and
(1) +a%2Fb+=+1%2F2+
(1) +a+=+%281%2F2%29%2Ab+
(1) +2a+=+b+
Substitute this into (2)
(2) +3%2A%282a%29+-+5a+=+6+
(2) +6a+-+5a+=+6+
(2) +a=+6+
and, since
(1) +2a+=+b+
(1) +b+=+12+
Their ages now are 6 and 12
check:
+6%2F12+=+1%2F2+
+%286%2B3%29%2F%2812%2B3%29+=+9%2F15+
+9%2F15+=+3%2F5+
OK
#2
Let a = Ashley's age now
Let b = Mary's age now
given:
(1) +a%2Fb+=+4%2F7+
(2) +a+%2B+b+=+22+
-------------
(1) +a+=+%284%2F7%29%2Ab+
Substitute this into (2)
(2) +%284%2F7%29%2Ab+%2B+b+=+22+
(2) +%2811%2F7%29%2Ab+=+22+
(2) +b+=+%287%2F11%29%2A22+
{2) +b+=+14+
and, since
(2) +a+%2B+b+=+22+
(2) +a+%2B+14+=+22+
(2) +a+=+8+
Ashley is 8 and Mary is 14
check answer:
(1) +a%2Fb+=+4%2F7+
(1) +8%2F14+=+4%2F7+
Multiply both sides by 14
(1) +8+=+8+
OK


Probability-and-statistics/533976: Six cards are deald from shuffle deck off played cards. even that all six cards are black, find the probability that they are all of the same suit. Let A and B represent the following event.
A=The cards are black
B=The six cards in same suit
1 solutions

Answer 351224 by josmiceli(9661) About Me  on 2011-11-18 17:19:30 (Show Source):
You can put this solution on YOUR website!
Since I know they are all black, they are all either
clubs or spades, and there are 26 of these.
The probability they are all the same suit is
+13%2F26+%2A+12%2F25+%2A+11%2F24+%2A+10%2F23+%2A+9%2F22+%2A+8%2F21+
+6%2F805+
A = 1
B = 6/805


Proportions/533977: Cost varies directly as time. The cost is $8 when the time is 2 hours.
What is the constant of proportionality?
1 solutions

Answer 351222 by josmiceli(9661) About Me  on 2011-11-18 17:05:41 (Show Source):


test/533995: Solve this problem by usonf the system.of substitution.
x-4y=4
6x-3y= -18
Help!!
1 solutions

Answer 351221 by josmiceli(9661) About Me  on 2011-11-18 17:02:29 (Show Source):
You can put this solution on YOUR website!
(1) +x+-+4y+=+4+
(2) +6x+-+3y+=+-18+
Divide both sides by 3
(2) +2x+-+y+=+-6+
----------------
Solve (1) for x
(1) +x+=+4+%2B+4y+
Substitute this into (2)
(2) +2%2A%284+%2B+4y%29+-+y+=+-6+
(2) +8+%2B+8y+-+y+=+-6+
(2) +7y+=+-6+-+8+
(2) +7y+=+-14+
(2) +y+=+-2+
and, since
(2) +2x+-+y+=+-6+
(2) +2x+-+%28-2%29+=+-6+
(2) +2x+%2B+2+=+-6+
(2) +2x+=+-8+
(2) +x+=+-4+
The solution +x+=+-4+, +y+=+-2+
It's easy to verify this with a plot of the equations:
+graph%28+400%2C+400%2C+-10%2C+10%2C+-10%2C+10%2C+%281%2F4%29%2Ax+-+1%2C+2x+%2B+6+%29+


Word_Problems_With_Coins/533991: Ricardo Guiterrez has a box of coins that he uses to play poker with friends. The box currently contains 38 coins, consisting of quarters, dimes and pennies. The number of pennies is equal to the number of dimes and the total value is $4.04. How many of each denomination of coin does Ricardo have?
1 solutions

Answer 351219 by josmiceli(9661) About Me  on 2011-11-18 16:45:06 (Show Source):
You can put this solution on YOUR website!
Let p = number of pennies
Let d = number of dimes
Let q = number of quarters
given:
(1) +p+%2B+d+%2B+q+=+38+
(2) +p+=+d+
(3) +p+%2B+10d+%2B+25q+=+404+ ( in cents )
----------------------
First substitute (2) into (1)
(1) +d+%2B+d+%2B+q+=+38+
(1) +q+=+38+-+2d+
Now substitute (1) and (2) into (3)
(3) +d+%2B+10d+%2B+25%2A%28+38+-+2d+%29+=+404+
(3) +11d+%2B+950+-+50d+=+404+
(3) +-39d+=+-950+%2B+404+
(3) +-39d+=+-546+
(3) +d+=+14+
and, since
(2) +p+=+d+
(2) +p+=+14+
and
(1) +q+=+38+-+2d+
(1) +q+=+38+-+28+
(1) +q+=+10+
Ricardo has 14 pennies, 14 dimes, and 10 quarters
check:
(3) +p+%2B+10d+%2B+25q+=+404+
(3) +14+%2B+10%2A14+%2B+25%2A10+=+404+
(3) +14+%2B+140+%2B+250+=+404+
(3) +404+=+404+
OK


Rate-of-work-word-problems/533989: If 5 workers take one hour to dig a ditch, how long will it take 12 workers to dig the same type of ditch (how many minutes)?
1 solutions

Answer 351218 by josmiceli(9661) About Me  on 2011-11-18 16:30:48 (Show Source):
You can put this solution on YOUR website!
5 workers take 60 minutes
1 worker will take 5 times as long, or 300 minutes
It will take 12 workers 1/12 of that time, or
300/12 = 25 minutes


Numbers_Word_Problems/533986: The sum of 2 consecutive odd integers is 92. Find the numbers.
If x represents the smaller integer, then the larger integer is
1 solutions

Answer 351217 by josmiceli(9661) About Me  on 2011-11-18 16:22:23 (Show Source):
You can put this solution on YOUR website!
Call the consecutive odd integers
+x+ and +x%2B2+
given:
+x+%2B+x+%2B+2+=+92+
+2x+=+90+
+x+=+45+
+x+%2B+2+=+47+
The numbers are 45 and 47


Miscellaneous_Word_Problems/533855: A salesman estimates that 30% of his usual sales, or $60,000, has been lost to a competitor. Find the value of the usual sales.
1 solutions

Answer 351187 by josmiceli(9661) About Me  on 2011-11-18 10:45:17 (Show Source):
You can put this solution on YOUR website!
Let x = his usual sales
given:
+.3x+=+60000+
+x+=+60000+%2F+.3+
+x+=+200000+
His usual sales is $200,000


Probability-and-statistics/533870: A card is drawn at random from a standard deck of playing cards where Aces are high. What is the probability that the card is less than a 8 given: the card is a club? Round your answer to two decimal places.

Answer:
1 solutions

Answer 351185 by josmiceli(9661) About Me  on 2011-11-18 10:42:15 (Show Source):
You can put this solution on YOUR website!
There are 13 clubs, and that's all you have to consider
What is the probability the card is
2,3,4,5,6,or 7 of clubs?
+6%2F13+=+.46+


Linear-systems/533880: the sum of the ages of prashant and his brother is 15 and the difference is 3.find their ages.
1 solutions

Answer 351184 by josmiceli(9661) About Me  on 2011-11-18 10:33:32 (Show Source):
You can put this solution on YOUR website!
Let their ages be a and b
+a+%2B+b+=+15+
+a+-+b+=+3+
-------------
add the equations
+2a+=+18+
+a+=+9+
and, since
+a+%2B+b+=+15+
+b+=+6+
Their ages are 6 and 9


Average/533879: My average score is 98% I have 7 days to get to 100% What average score would I have to get each day to make it to 100%?
1 solutions

Answer 351183 by josmiceli(9661) About Me  on 2011-11-18 10:30:06 (Show Source):
You can put this solution on YOUR website!
You can never get there
Suppose the 98% was the result of just 1 test,
and suppose you got 100% for the next 7 tests,
then your average is
+%2898+%2B+700%29+%2F+8+=+798%2F8+
+798%2F8+=+99.75+
That's the best you can do.


Probability-and-statistics/533872: Sam has 17 ties. He has 6 green, 3 blue and 8 red. If he selects two ties at random, what is the probability that both ties are different colors? Round your answer to two decimal places.

Answer:
1 solutions

Answer 351182 by josmiceli(9661) About Me  on 2011-11-18 10:24:12 (Show Source):
You can put this solution on YOUR website!
I would first find the probability
that both ties are the same
Both green: +%286%2F17%29%2A%285%2F16%29+
Both blue: +%283%2F17%29%2A%282%2F16%29+
Both red: +%288%2F17%29%2A%287%2F16%29+
The ties are the same color if he has
( both green ) OR ( both blue ) OR ( both red )
When things are OR'd you add the probabilities

+%28+1+%2F+%28+17%2A16+%29+%29%2A%28++6%2A5+%2B+3%2A2+%2B+8%2A7+%29+
+%28+1%2F272+%29%2A%28+30+%2B+6+%2B+56+%29+
+92+%2F+272+=+23%2F68+
The probability that none of these happen is
+1+-+23%2F68+=+45%2F68+
That would be better than 50-50 odds
I would get a 2nd opinion on this. I'm in
kind of deep water with probabilities


test/533863: The coordinates of the endpoints of a segment are I(-2,1)and j(6,3). What are the coordinates of the midpoints of the segment?
1 solutions

Answer 351176 by josmiceli(9661) About Me  on 2011-11-18 10:05:36 (Show Source):
You can put this solution on YOUR website!
Find the midpoints of the x-components
and then the y-components
Mid(x) = +%28+6+%2B+%28-2%29+%29+%2F+2+
Mid(x) = +4%2F2+
Mid(x) = +2+
and
Mid(y) = +%28+3+%2B+1+%29+%2F+2+
Mid(y) = +4%2F2+
Mid(y) = +2+
The midpoint is at (2,2)


Points-lines-and-rays/533655: what is the square root of 18 divided by the square root of 10?
1 solutions

Answer 351100 by josmiceli(9661) About Me  on 2011-11-17 21:00:04 (Show Source):


Proportions/533617: Suppose that Julian has 44 coins consisting of pennies and nickels. If the number of nickels is two more than, twice the number of pennies , find the number of coins of each kind?
1 solutions

Answer 351094 by josmiceli(9661) About Me  on 2011-11-17 20:11:28 (Show Source):
You can put this solution on YOUR website!
Let p = number of pennies
Let n = number of nickels
given:
(1) +n+%2B+p+=+44+
(2) +n+=+2p+%2B+2+
Substitute (2) into (1)
(1) +2p+%2B+2+%2B+p+=+44+
(1) +3p+=+44+-+2+
(1) +3p+=+42+
(1) +p+=+14+
and, since
(2) +n+=+2p+%2B+2+
(2) +n+=+2%2A14+%2B+2+
(2) +n+=+28+%2B+2+
(2) +n+=+30+
There are 14 pennies and 30 nickels


Proportions/533619: So I've been working on this word problem for about an hour and I'm not getting it at all. Here it is:
"A hybrid car averages 601 miles on a 12.2 gallon tank of gas. Manuel is planning a 1280-mile vacation in his hybrid car. Find how many gallons of gas he can expect to burn."
If you guys could help me, that would be awesome.
1 solutions

Answer 351093 by josmiceli(9661) About Me  on 2011-11-17 20:04:43 (Show Source):
You can put this solution on YOUR website!
In units alone:
( gallons / mile ) x miles = gallons
+%28+12.2+%2F+601+%29%2A1280+=+25.98+
He will burn 25.98 gallons


Linear_Equations_And_Systems_Word_Problems/533457: Find the amount of twenty five percent acid solution and the amount of a fifteen percent acid solution that combine to prepare fifty oz at an eighteen percent acid solution.
1 solutions

Answer 351092 by josmiceli(9661) About Me  on 2011-11-17 19:58:12 (Show Source):
You can put this solution on YOUR website!
Let a = ounces of 25% solution needed
Let b = ounces of 15% solution needed
given:
+.25a+ = ounces of acid in 25% solution
+.15b+ = ounces of acid in 15% solution
----------------------------------
given:
(1) +a+%2B+b+=+50+
(2) +%28+.25a+%2B+.15b+%29+%2F+50+=+.18+
-------------------------
(2) +.25a+%2B+.15b+=+.18%2A50+
(2) +.25a+%2B+.15b+=+9+
(2) +25a+%2B+15b+=+900+
(2) +5a+%2B+3b+=+180+
Multiply both sides of (1) by 3, and
subtract (1) from (2)
(2) +5a+%2B+3b+=+180+
(1) +-3a+-+3b+=+-150+
+2a+=+30+
+a+=+15+
and, since
(1) +a+%2B+b+=+50+
(1) +15+%2B+b+=+50+
(1) +b+=+35+
15 ounces of 25% solution are needed
35 ounces of 15% solution are needed
check:
(2) +%28+.25%2A15+%2B+.15%2A35+%29+%2F+50+=+.18+
(2) +%28+3.75+%2B+5.25+%29+%2F+50+=+.18+
(2) +9%2F50+=+.18+
(2) +9+=+9+
OK


Polynomials-and-rational-expressions/533467: Factor completely: 5x^3-45x
1 solutions

Answer 351065 by josmiceli(9661) About Me  on 2011-11-17 16:43:43 (Show Source):
You can put this solution on YOUR website!
+5x%5E3+-+45x+=+x%2A%28+5x%5E2+-+45+%29+
+x+=+0+ is a solution, also,
+5x%5E2+-+45+=+0+
+5x%5E2+=+45+
+x%5E2+=+9+
+x+=+3+
+x+=+-3+
+x+=+0+
are the 3 solutions


Numeric_Fractions/533460: What is 4/5 divided by 4/3?
1 solutions

Answer 351064 by josmiceli(9661) About Me  on 2011-11-17 16:39:39 (Show Source):
You can put this solution on YOUR website!
+%284%2F5%29+%2F+%284%2F3%29+
You can think of this as
+%28+1%2F%284%2F3%29+%29%2A%284%2F5%29+
and
+1%2F%284%2F3%29+=+3%2F4+, so
+%284%2F5%29+%2F+%284%2F3%29+=+%284%2F5%29%2A%283%2F4%29+
+%284%2F5%29%2A%283%2F4%29+=+12%2F20+
+12%2F20+=+3%2F5+


Equations/533419: I have a math problem that say this: Constance has $2.80 in quarters and dimes. The number of quarters exceeds three times the number of dimes by 1. Find the number she has of each kind. What do they mean by 1?
1 solutions

Answer 351061 by josmiceli(9661) About Me  on 2011-11-17 15:49:02 (Show Source):
You can put this solution on YOUR website!
They mean that she has 3 times as many quarters as dimes
plus 1 more quarter.
For example, if she had 5 dimes, then she would have
+3%2A5+ = 15 quarters plus 1 more quarter = 16 quarters
----------------
As for your problem,
Let q = number of quarters she has
Let d = number of dimes she has
given:
(1) +q+=+3d+%2B+1+
(2) +25q+%2B+10d+=+280+ ( in cents )
---------------------
Divide both sides of (2) by 5
(2) +5q+%2B+2d+=+56+
Substitute (1) into (2)
(2) +5%2A%28+3d+%2B+1+%29+%2B+2d+=+56+
(2) +15d+%2B+5+%2B+2d+=+56+
(2) +17d+=+51+
(2) +d+=+3+
and, since
(1) +q+=+3d+%2B+1+
(1) +q+=+3%2A3+%2B+1+
(1) +q+=+10+
She has 10 quarters and 3 dimes


Average/533378: i have 43 questions how many can i miss to get 85%
1 solutions

Answer 351057 by josmiceli(9661) About Me  on 2011-11-17 15:36:50 (Show Source):
You can put this solution on YOUR website!
Let x = number that you have to answer correctly
+x%2F43+=+.85+
+x+=+.85%2A43+
+x+=+36.55+
The next whole number is 37, so the
number you can miss and get 85% right
is +43+-+37+ = 6


Permutations/533390: How many five-digit numbers can be formed using the digits 0,1,2,3,4,5,6,7,8,&9 if the first digit cannot be 0 or 1? Repeated digits are allowed
1 solutions

Answer 351051 by josmiceli(9661) About Me  on 2011-11-17 15:19:43 (Show Source):
You can put this solution on YOUR website!
There are 8 choices for the 1st digit
There are 10 choices for the remaining digits
There can be +8%2A10%5E4+, or
80,000 possible numbers


Probability-and-statistics/533381: Pick& Save grocery stores in Wisconsin are giving out scratch off tickests when you buy groceries . There are nine symbols covered up. Three of them are the same. You have to scratch off the three identical ones to win. What are the odds of picing three of the same out of nine?
1 solutions

Answer 351049 by josmiceli(9661) About Me  on 2011-11-17 15:13:39 (Show Source):
You can put this solution on YOUR website!
For the 1st scratch, you have +3%2F9+ probability
For the 2nd scratch, you have +2%2F8+ probability
For the 3rd scratch, you have +1%2F7+ probability
+%283%2F9%29%2A%282%2F8%29%2A%281%2F7%29+=+6%2F504+
+6%2F504+=+1%2F84+
In terms of odds, that is 83 to 1 against
I think this is right, you might want another opinion


Linear_Equations_And_Systems_Word_Problems/533384: Please help me solve this
"the price of stick in XYZ Corporation was $74 two weeks ago. Seven weeks ago, the price was $59 a share"

Answer and explain ASAP PLEASE!!!!
1 solutions

Answer 351048 by josmiceli(9661) About Me  on 2011-11-17 15:03:50 (Show Source):
You can put this solution on YOUR website!
You left out the question.
What is it you are trying to find?


Numbers_Word_Problems/533268: Word problem: Bruce was a pupil at Madison Elemnetary School in 1945. The year of his birth is a perfect square. How old was he on his birthday in 1988?
Another word problem: In a group of cows and turkeys, the number of heads is 35 less than the number of legs. What is the largest number of cows that could be in this group of animals?
1 solutions

Answer 351047 by josmiceli(9661) About Me  on 2011-11-17 15:01:59 (Show Source):
You can put this solution on YOUR website!
I try to think of numbers that are
around 1945 when you square them.
+50%2A50+=+2500+ too high
+40%2A40+=+1600+ too low
+45%2A45+=+2025+ too high
+44%2A44+=+1936+ just right
That would make Bruce 9 years old
( depending on the month he was born )
In 1988 on his birthday, Bruce would
be exactly +1988+-+1936+=+52+
52 years old
-------------------------------
Let +c+ = number of cows
Let +t+ = number of turkeys
Number of heads = +c+%2B+t+
Number of legs = +4c+%2B+2t+
given:
+c+%2B+t+=+4c+%2B+2t+-+35+
This is 1 equation with 2 unknowns, so it
isn't directly solvable, but I can make guesses
Subtract c from both sides
+t+=+3c+%2B+2t+-+35+
Subtract t from both sides
+0+=+3c+%2B+t+-+35+
Add 5 to both sides
+3c+%2B+t+=+35+
What if there are 10 cows?
+3%2A10+%2B+t+=+35+
+t+=+35+-+30+
+t+=+5+
What if there are 11 cows?
+3%2A11+%2B+t+=+35+
+t+=+35+-+33+
+t+=+2+
What if there are 12 cows?
+3%2A12+%2B+t+=+35+
+t+=+35+-+36+
There can't be minus one turkey, so
the largest possible number of cows
is 11
check answer:
+c+%2B+t+=+4c+%2B+2t+-+35+
+11+%2B+t+=+4%2A11+%2B+2t+-+35+
+11+%2B+t+=+9+%2B+2t+
Subtract 9 from both sides
+2+%2B+t+=+2t+
Subtract t from both sides
+t+=+2+
That's correct