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nerdybill answered: 7006 problems
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Geometry_Word_Problems/316116: Rachel ran 3375 feet.how many feet less than 0.75 mile is this? 1 solutions Answer 226125 by nerdybill(7008)   on 2010-06-21 00:57:59 (Show Source): You can put this solution on YOUR website! Rachel ran 3375 feet.how many feet less than 0.75 mile is this? . Since there are 5280 feet in a mile: .75(5280) = 3960 feet . 3960-3375 = 585 feet

Probability-and-statistics/316100: Tim was ranked 50th in a class of 250. What was his percentile rank? 1 solutions Answer 226124 by nerdybill(7008)   on 2010-06-21 00:55:29 (Show Source): You can put this solution on YOUR website! Tim was ranked 50th in a class of 250. What was his percentile rank? . (250-50)/250 * 100 = 200/250 *100 = .8 *100 = 80%

Mixture_Word_Problems/316114: a pharmacist has 20 L of a 10% drug solution. How many liters of 5% solution must be added to get a mixture that is 8% ? 1 solutions Answer 226123 by nerdybill(7008)   on 2010-06-21 00:52:33 (Show Source): You can put this solution on YOUR website! a pharmacist has 20 L of a 10% drug solution. How many liters of 5% solution must be added to get a mixture that is 8% ? . Let x= liters of 5% solution added then .05x + .10(20) = .08(20+x) .05x + 2 = 1.6+.08x 2 = 1.6+.08x .4 = .08x 5 liters = x

Travel_Word_Problems/316087: Viral can do a piece of work in 10 days & Raja in 15days. If both of them work together how long will it take to finish the work? a) 6days b) 5days c) 7days d) 8days 1 solutions Answer 226121 by nerdybill(7008)   on 2010-06-21 00:48:07 (Show Source): You can put this solution on YOUR website! Viral can do a piece of work in 10 days & Raja in 15days. If both of them work together how long will it take to finish the work? a) 6days b) 5days c) 7days d) 8days . Let x = time it takes for both then x(1/10 + 1/15) = 1 x(15 + 10) = 150 x(25) = 150 x = 6 days

logarithm/316093: 1. Solve log(6x+5)=0 2. use natural logarithms to solve this equation. Round to the nearest thousandeth. 6e^4x-6=15 3.e^x=3/4 1 solutions Answer 226119 by nerdybill(7008)   on 2010-06-21 00:38:28 (Show Source): You can put this solution on YOUR website! 1. Solve log(6x+5)=0 6x+5 = 10^0 6x+5 = 1 6x = -4 x = -4/6 x = -2/3 . 2. use natural logarithms to solve this equation. Round to the nearest thousandeth. 6e^4x-6=15 6e^4x=21 e^(4x)^6=21 (4x)^6 = ln(21) 4x = (ln(21))^(1/6) x = ((ln(21))^(1/6))/4 x = 0.301 . 3.e^x=3/4 x = ln(3/4) x = -0.288

percentage/316040: Brett a football player made 18 field goals out of 22 attempted field goals. To the nearest whole percent,what persent of the field goals were successful? 1 solutions Answer 226075 by nerdybill(7008)   on 2010-06-20 20:06:10 (Show Source): You can put this solution on YOUR website! 18/22 * 100 = 0.818*100 = 81.8% rounded to nearest percent: 82%

Mixture_Word_Problems/316001: twenty pounds of salt-water solution contains fifteen percent salt. How much water must be added to weaken the solution to twelve percent salt? 1 solutions Answer 226073 by nerdybill(7008)   on 2010-06-20 19:56:20 (Show Source): You can put this solution on YOUR website! twenty pounds of salt-water solution contains fifteen percent salt. How much water must be added to weaken the solution to twelve percent salt? . Let x = pounds of water to add then .15(20) = .12(20+x) 3 = 2.4 + .12x .6 = .12x .6/.12 = x 5 pounds = x

Square-cubic-other-roots/315970: in a right triangle, find the length of the sides when a is unknown, b=1 and c=square root 26 1 solutions Answer 226009 by nerdybill(7008)   on 2010-06-20 15:28:09 (Show Source): You can put this solution on YOUR website! in a right triangle, find the length of the sides when a is unknown, b=1 and c=square root 26 . For any "right triangle", you can apply Pythagorean theorem: .

Miscellaneous_Word_Problems/315935: filling a tank through a large tube takes 30 minutes. It takes 50 minutes for the tank to fully drain through a smaller tube. how long will it take to fill the tank if both tubes are open 1 solutions Answer 226003 by nerdybill(7008)   on 2010-06-20 13:17:55 (Show Source): You can put this solution on YOUR website! filling a tank through a large tube takes 30 minutes. It takes 50 minutes for the tank to fully drain through a smaller tube. how long will it take to fill the tank if both tubes are open . Let x = time it takes to fill tank when both tubes are open then x(1/30 - 1/50) = 1 Multiplying both sides by 1500: x(50 - 30) = 1500 x(20) = 1500 x = 75 minutes

Polynomials-and-rational-expressions/315936: 2x^2+4x=0 1 solutions Answer 226002 by nerdybill(7008)   on 2010-06-20 13:15:26 (Show Source): You can put this solution on YOUR website! 2x^2+4x=0 Factor what is common between the two terms first: (2x)(x+2)=0 . Setting each term to zero: x = {0, -2}

Rational-functions/315903: Find the point of intersection of the two lines: 3x-4y=2 -2x+y=1 Thanks in advance 1 solutions Answer 225996 by nerdybill(7008)   on 2010-06-20 10:45:42 (Show Source): You can put this solution on YOUR website! . The point of intersection is simply the solution to: 3x-4y=2 -2x+y=1 Solve by the addition method. Multiply the bottom equation by 4 and add: 3x-4y=2 -8x+4y=4 ----------- -5x = 6 x = -6/5 . Plug above into second equation and solve for y: -2x+y=1 -2(-6/5)+y=1 12/5+y=1 y = 1-12/5 y = 5/5-12/5 y = -7/5 . Point of intersection: (-6/5, -7/5)

logarithm/315786: log (base x)0.05 = -1/2 1 solutions Answer 225966 by nerdybill(7008)   on 2010-06-20 00:56:05 (Show Source): You can put this solution on YOUR website!

logarithm/315738: Express as a single logarithm, and, if possible, simplify. logb 5x + 7(logb x - logb y) 1 solutions Answer 225901 by nerdybill(7008)   on 2010-06-19 14:35:54 (Show Source): You can put this solution on YOUR website!

Polynomials-and-rational-expressions/315759: List all numbers for which the rational expression is undefined x^2-4/x^2-8x+15 1 solutions Answer 225900 by nerdybill(7008)   on 2010-06-19 14:31:54 (Show Source): You can put this solution on YOUR website! Undefined if the denominator is zero so we set x^2-8x+15 to zero and solve for x . x^2-8x+15 = 0 (x-5)(x+3) = 0 x = {-3, 5}

expressions/315755: Please help me to evaluate: a+(b-a)^2, for a=1 and b=2. My answer is 3, but it's answer is 2? Thanks in advance 1 solutions Answer 225899 by nerdybill(7008)   on 2010-06-19 14:30:19 (Show Source): You can put this solution on YOUR website! a+(b-a)^2, for a=1 and b=2 . Plugging in the values: 1+(2-1)^2 1+(1)^2 1+1 2

Probability-and-statistics/315729: In a box of 14 clocks, it is known that three clocks are defective. Two clocks are selected at random without replacement. Find the probability that both clocks are defective. 1 solutions Answer 225882 by nerdybill(7008)   on 2010-06-19 11:19:01 (Show Source): You can put this solution on YOUR website! In a box of 14 clocks, it is known that three clocks are defective. Two clocks are selected at random without replacement. Find the probability that both clocks are defective. . 3/14 * 2/13 = 6/182 = .033

Percentage-and-ratio-word-problems/315708: Gwen bought a new Toyota Corolla. The selling price plus the 8% state sales tax was $15,714. What was the selling price? 1 solutions Answer 225881 by nerdybill(7008)   on 2010-06-19 11:15:50 (Show Source): You can put this solution on YOUR website! The selling price plus the 8% state sales tax was $15,714. What was the selling price? . Let P = selling price then P + .08P = 15714 P(1+.08) = 15714 P(1.08) = 15714 P = 15714/1.08 P = $14,550

Finance/315681: a college paid $1748 for 46 calculators. They paid $9 for each scientific calculator. all other graphing calculators cost $55 each how many of each calculator was ordered 1 solutions Answer 225863 by nerdybill(7008)   on 2010-06-19 02:14:44 (Show Source): You can put this solution on YOUR website! a college paid $1748 for 46 calculators. They paid $9 for each scientific calculator. all other graphing calculators cost $55 each how many of each calculator was ordered . Let x = number of scientific calculators then 46-x = number of graphing calculators . 9x + 55(46-x) = 1748 9x + 2530 - 55x = 1748 2530 - 46x = 1748 -46x = -782 x = 17 (number of scientific calculators) . graphing calculators: 46-x = 46-17 = 29

logarithm/315585: logarithm using the change-of-base formula. Round to the nearest ten-thousandth. log8.1 5.6 1 solutions Answer 225836 by nerdybill(7008)   on 2010-06-18 21:47:48 (Show Source): You can put this solution on YOUR website! I'll assume you mean: Applying change of base we get: = =

logarithm/315415: Solve: ln(2x+3)=3 1 solutions Answer 225700 by nerdybill(7008)   on 2010-06-18 01:49:44 (Show Source): You can put this solution on YOUR website! ln(2x+3)=3 2x+3 = e^3 2x = e^3-3 x = (e^3-3)/2 x = 8.543

Age_Word_Problems/315294: Gabrielle is 15 years younger than Mikhail. The sum of their ages is 81 . What is Mikhail's age? 1 solutions Answer 225610 by nerdybill(7008)   on 2010-06-17 17:08:50 (Show Source): You can put this solution on YOUR website! Gabrielle is 15 years younger than Mikhail. The sum of their ages is 81 . What is Mikhail's age? . Let x = Mikhail's age then x-15 = Gabrielle's age . x + x-15 = 81 2x-15 = 81 2x = 96 x = 48 years old

Rate-of-work-word-problems/315312: Two college students have started their own business building computers from kits. Working alone, one student can build a computer in 20 hours. When the second student helps, they can build a computer in 7.5 hours. How long would it take the second student, working alone, to build the computer. 1 solutions Answer 225609 by nerdybill(7008)   on 2010-06-17 17:07:12 (Show Source): You can put this solution on YOUR website! Two college students have started their own business building computers from kits. Working alone, one student can build a computer in 20 hours. When the second student helps, they can build a computer in 7.5 hours. How long would it take the second student, working alone, to build the computer. . Let x = time it takes second student to build it alone then 7.5(1/20 + 1/x) = 1 Multiplying both sides by 20x: 7.5(x + 20) = 20x 7.5x + 150 = 20x 150 = 12.5x 12 hours = x

Travel_Word_Problems/315309: a student took 18 minutes to walk from home to school.given that his average speed is 4km/h,how far he had to travel 1 solutions Answer 225605 by nerdybill(7008)   on 2010-06-17 17:04:23 (Show Source): You can put this solution on YOUR website! a student took 18 minutes to walk from home to school.given that his average speed is 4km/h,how far he had to travel . Apply the distance formula: d = rt . However, begin by changing the 18 minutes into hours: 18min * 1hr/60min = 18/60 = 3/10 hour . distance = 3/10 * 4 distance = 3/5 * 2 distance = 6/5 km or distance is 1.2 km

Angles/315281: The measure of an angle is 20 less than 3 times its supplement. Find the measure of the angle 1 solutions Answer 225604 by nerdybill(7008)   on 2010-06-17 17:01:11 (Show Source): You can put this solution on YOUR website! The measure of an angle is 20 less than 3 times its supplement. Find the measure of the angle . Let x = the angle then 180-x = the supplement . x = 3(180-x) - 20 x = 540-3x-20 x = 520-3x 4x = 520 x = 130 degrees

logarithm/315283: find the logarith using the change-of-base formula. logn 1500 1 solutions Answer 225567 by nerdybill(7008)   on 2010-06-17 15:57:28 (Show Source): You can put this solution on YOUR website! That would be log(1500)/log(n)

logarithm/315262: evaluate the logarithm. 1. log (base 7) 1/49 write the expression as a single logarithm 2. 5log (base b)q+3 log(base b)w 3. 4 log x-6 log (x+2) 4. solve 4^2x=111 1 solutions Answer 225542 by nerdybill(7008)   on 2010-06-17 14:40:02 (Show Source): You can put this solution on YOUR website! 1. log (base 7) 1/49 write the expression as a single logarithm 2. 5log (base b)q+3 log(base b)w 3. 4 log x-6 log (x+2) 4. solve 4^2x=111

Quadratic_Equations/315258: A sandbag falls out of a hot air balloon that is 144 feet above the ground how long does it take for the sandbag to reach the ground? 1 solutions Answer 225538 by nerdybill(7008)   on 2010-06-17 14:23:47 (Show Source): You can put this solution on YOUR website! h(t) = -(1/2)32t^2 + Vt + Ho where h(t) is height t is time V is initial velocity (0) Ho is initial height (144) . 0 = -(1/2)32t^2 + 0t + 144 0 = -16t^2 + 144 -144 = -16t^2 9 = t^2 3 sec = t

Exponents/315228: How do you solve problems like this? 324=4(3^n-1) thank you 1 solutions Answer 225519 by nerdybill(7008)   on 2010-06-17 12:33:21 (Show Source): You can put this solution on YOUR website! I'm assuming the (n-1) is the exponent -- if not, please write back. .

logarithm/315214: solve. where appropriate, include approximations to the nearest thousandth. if no solution exists, state this 5^x = 125 1 solutions Answer 225510 by nerdybill(7008)   on 2010-06-17 11:55:10 (Show Source): You can put this solution on YOUR website! 5^x = 125 x = x = x =3

logarithm/315212: solve. where appropriate, include approximations to the nearest thousandth. if no solution exists, state this In 8x=5 1 solutions Answer 225507 by nerdybill(7008)   on 2010-06-17 11:53:50 (Show Source): You can put this solution on YOUR website! ln 8x=5 8x = e^5 x = e^5/8 x = 18.55

Human-and-algebraic-language/315205: Jim is able to sell a hand-carved statue for $670 which was a 35% profit over his cost. How much did the statue originally cost him? 1 solutions Answer 225506 by nerdybill(7008)   on 2010-06-17 11:51:59 (Show Source): You can put this solution on YOUR website! Jim is able to sell a hand-carved statue for $670 which was a 35% profit over his cost. How much did the statue originally cost him? . Let x = original cost then x + .35x = 670 x(1 + .35) = 670 1.35x = 670 x = 670/1.35 x = $496.30