Questions on Algebra: Proportions answered by real tutors!

Tutors Answer Your Questions about Proportions (FREE)

Question 1006346: A bag of batteries in the ratio of 3 size D batteries to 7 size C batteries is combined with a bag having a ratio of 5 size D to 1 size C.
If the two bags together now contain an equal number of size D and C batteries, how many batteries are in the second bag?
My attempt:
Step 1: I can see that the first bag in the ratio of 3/7 has 18 size D batteries and 42 size C batteries, given that the total number in the bag is 60.
Step 2: I can see that the second bag is in the ratio of 5/1.
Step 3: Through trial and error, I can see that I need to get to a combined bag with a ratio of 8/8 for a total of 96. But I don't know how to do this mathematically.
This is often my problem. Can anybody help me set this up?
Thank you.

Click here to see answer by Theo(13342)

Question 1006629: Translate each statement into a mathematical statement. Use k as the constant of variation:
1. M varies jointly as p and q.
2. Y varies directly as x and inversely as the square of z.
3. The time required to travel is directly proportional to the temperature and inversely proportional to the pressure P.
4. The heat H produced by an electric lamp varies jointly as the resistance R and the square of the current C.
Click here to see answer by Cromlix(4381)

Question 1006631: In the formula p^2=mb/t, how does p change when m remains constant, b is doubled, and t is halved?
Click here to see answer by MathLover1(20850)

Question 1007586: 6 Kangaroos eat 6 sacks in six minutes then how many Kangaroos eats 100 sacks in 100 minutes?
Click here to see answer by fractalier(6550)

Question 1008021: For every 2 salt and vinegar crisps, there are 4 packets of plain crisps, 3 packets of cheese and onion crisps and 1 packet of prawn cocktail crisps.
How many salt and vinegar flavour packets are there if total number of packets is 50 ?
Kindly help :/
Click here to see answer by Theo(13342)

Question 1008195: On a train, 45% of the passengers are women, 30% are men and 25% are children.
If there are 120 more women than men on the train, how many children are on the train?
Click here to see answer by jim_thompson5910(35256)

Question 1008688: two number have the ratio 3:4 if 5 is subtracted from each of the number the difference have ratio of 1:3 find the number
Click here to see answer by MathLover1(20850)

Question 1008688: two number have the ratio 3:4 if 5 is subtracted from each of the number the difference have ratio of 1:3 find the number
Click here to see answer by stanbon(75887)

Question 1008901: For every 2 salt and vinegar crisps, there are 4 packets of plain crisps, 3 packets of cheese and onion crisps and 1 packet of prawn cocktail crisps.
What is the total number of packet of crisps if there are 12 packets of prawn cocktail?
Click here to see answer by josmiceli(19441)

Question 1009040: If y is directly proportional to the square root of x and y = −32 when x = 400, find y if x = 160000. (Round off your answer to the nearest hundredth.)
Click here to see answer by MathLover1(20850)

Question 1009051: Kara and San shared a cash prize in the ratio 3:7. If San received $77, how much money did Kara receive?
Click here to see answer by fractalier(6550)

Question 1009686: If an automobile runs 36 miles on 2 gallons of gas, how many miles will it run on 12 gallons?
Click here to see answer by macston(5194)

Question 1009688: Using k as a constant of proportionality, write the equation that express the following statement: Z varies jointly x and y.
Click here to see answer by ikleyn(52781)

Question 1009685: If a mast 8 ft high casts a shadow of 10ft long, how high is a mast that casts a shadow 40ft long?
Click here to see answer by fractalier(6550)

Question 1009684: a man can read 400 words per minute compared to the 250 words per minute of the average reader. how much faster does this man read compared to an average reader?
Click here to see answer by fractalier(6550)

Question 1010433: A recipe for chocolate chip cookies calls for 3/4 cup brown sugar for every 2 1/4 cups of flour.
If 2 5/8 cups of brown sugar are used, how much flour will be needed?
Click here to see answer by stanbon(75887)

Question 1010657: Which of the following is NOT a proportion? :
3/2=15/10
17/4=85/20
8/3=48/18
11/13=66/91
Click here to see answer by Edwin McCravy(20055)

Question 1010770: a plane is at X(5,-2) and it has to travel to either Y(-2,6) or Z(9,8). which point is closer? by how much? round to the nearest tenth
Click here to see answer by MathLover1(20850)

Question 1012045: The 250 soldiers in a camp had enough food for forty days, After 10 days, 50 soldiers joined them. For how long will the remaining food last them? Solve using variation.
Click here to see answer by ValorousDawn(53)

Question 1012174: the number of red poinsettia plants is 25 more than 7 time the number of white ones. there are 225 total. how many are white.
Click here to see answer by macston(5194)

Question 1012389: An 8-inch By 10-inch Photo Is Being Reduced Proportionally. The 10-inch Side Is Reduced By X Inches. What Is The CHANGE In The Area In Terms Of X?
Click here to see answer by Alan3354(69443)

Question 1012794: The scale model of a building is 5.4 feet tall.
A) If the original building is 810 meters tall, what was the scale used to make the model?
B) If the model is made out of tiny bricks each measuring 0.4 inch in height, how many bricks tall is the model?
Click here to see answer by macston(5194)

Question 1012814: In this problem what is the domain of f(x)=2x/5x-25
Click here to see answer by ikleyn(52781)

Question 1012948: A 8 in. by 10 in. photo is reduced so that the width (the shorter dimension) is 3 in. What is the length of the reduced photo?
Click here to see answer by hatcher.roxanne@gmail.com(1)

Question 1012948: A 8 in. by 10 in. photo is reduced so that the width (the shorter dimension) is 3 in. What is the length of the reduced photo?
Click here to see answer by ikleyn(52781)

Question 1013152: if it takes 5 minutes to get one point how many minutes what it take to get 90 points
Click here to see answer by Pinksparkles(13)

Question 1013152: if it takes 5 minutes to get one point how many minutes what it take to get 90 points
Click here to see answer by fractalier(6550)

Question 1013292: Hello
I have the answers to the following questions but am not sure of the process to solve them. Thanks for the help.
2 people throw a ball at the same time. One of them hits the target 55 out of 100 times, and the other one hits it 95 out of 100 times.
What is the probability that exactly one of the throws Will hit the target?
(answer: 91 / 200 )
What is the probability that at least one of the throws will hit the target?
( 391 / 400 )

Click here to see answer by Boreal(15235)

Question 1013369: So my question is how I would solve this proportion:
2x/4=5x+6/3
I also wanted to check if I did this proportion correctly:
5/3x=7
I multiplied the 5/3 by 3/5 and then I got an answer of x=7. Was I supposed to multiply 5/3x by 1/5? Thank you for helping!
Click here to see answer by Boreal(15235)

Question 1013408: Solve this proportion:
3+x/7=3x-7/3
I did most of the work and ended up with x=-29/9. Is that what x equals? Also, how would I apply that answer to the existing equation? Please show your work and thank you!
Click here to see answer by josgarithmetic(39617)

Question 1013446: Hello,
I guess I am really lost, I posted a question yesterday and someone was nice enough to post an answer but I don't understand where the numbers came from.
Here was the question:
I have the answers to the following questions but am not sure of the process to solve them. Thanks for the help.
2 people throw a ball at the same time. One of them hits the target 55 out of 100 times, and the other one hits it 95 out of 100 times.
What is the probability that exactly one of the throws Will hit the target?
(answer: 91 / 200 )
What is the probability that at least one of the throws will hit the target?
( 391 / 400 )
Here is the answer posted:
The probability that one only hits is (0.55)(0.05)=0.0275+ (0.45)(0.95)=0.4275
They add up to 0.4550, or 45.5%, which is 91/200.
At least one is 1-probability that both miss. That is 0.45*0.05=0.0225
That is 2.25% or 2.25 per 100 or 9 per 400 that both miss. Subtract 9 from 400 and 391/400 is the probability that at least 1 will hit.
Where did .05 and .45 come from?
Thanks.

Click here to see answer by macston(5194)

Question 1013734: If the width of a rectangle is 144cm, and the perimeter is 7.8 meters, what is the ratio of the width of the rectangle to its length?
I have converted 7.8 meter to 780 cm. Then I solved 780/144. I keep on getting a long decimal. Am I doing it right?
Thank you for helping.
Click here to see answer by Theo(13342)

Question 1013841: If a:b =c:d =5:7, find (a+c):(b+d).
Click here to see answer by MathLover1(20850)

Question 1013841: If a:b =c:d =5:7, find (a+c):(b+d).
Click here to see answer by Theo(13342)

Question 1014148: WHAT IS THE DIFFERENCE IN MILES PER HOUR, BETWEEN MRCUS SWIMMING SPEED AND HIS HIKING SPEED?
SWIM- DISTANCE IN MILES 5/8 AND TIME( IN HOURS) 1/4

HIKE-DISTANCE IN MILES 3/4 AND TIME( IN HOURS) 1/3
KAYAK-DISTANCE IN MILES 2/3 AMD TIME(IN HOURS) 1/6
IN WHICH SPORT IS MARCUS SPEED THE FASTEST?
Click here to see answer by Boreal(15235)

Question 1014270: Using the scale of 1/2cm + 75km, how many kilometers would each distance represent?
4 1/2 cm =
2 1/4 cm =
5 3/4 cm =

Click here to see answer by Alan3354(69443)

Question 1014363: If then prove that
Click here to see answer by Edwin McCravy(20055)

Question 1014450: Describe a proportional situation that is represented by the equation y=6x.
Click here to see answer by fractalier(6550)

Question 1014775: 125m on the ground corresponds to 2.5 cm on a map. What is the actual distance between two objects if, on the map, they are 4.2 cm apart?
Click here to see answer by stanbon(75887)

Question 1014920: y varies directly as the cube of x and square of z. if x = 2 and y = 3. what is y, if x =4 and z = 9.
Click here to see answer by robertb(5830)

Question 1014920: y varies directly as the cube of x and square of z. if x = 2 and y = 3. what is y, if x =4 and z = 9.
Click here to see answer by ikleyn(52781)

Question 1014925: Edit:
Sorry for the post that have insufficient data, i checked again the problem and here it is:
y varies directly as the cube of x and square of z. If y = 5, if x = 2, & z = 3, what is y if x = 4 & z = 9?
thank you
Click here to see answer by ikleyn(52781)

Question 1014926: y varies directly as the square of x and inversely as the square root of z. if x is quadrupled and z is multiplied by 8, How much will y change?
Click here to see answer by ikleyn(52781)

Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510, 3511..3555, 3556..3600, 3601..3645, 3646..3690, 3691..3735, 3736..3780, 3781..3825, 3826..3870, 3871..3915, 3916..3960, 3961..4005, 4006..4050, 4051..4095, 4096..4140, 4141..4185, 4186..4230, 4231..4275, 4276..4320, 4321..4365, 4366..4410, 4411..4455, 4456..4500, 4501..4545, 4546..4590, 4591..4635, 4636..4680, 4681..4725, 4726..4770, 4771..4815, 4816..4860, 4861..4905, 4906..4950, 4951..4995, 4996..5040, 5041..5085, 5086..5130, 5131..5175, 5176..5220, 5221..5265