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Hey everyone, I had a few (or seven) math problems I feel stupid that I can't do cause its been so long (now i'm making excuses). They've been collecting over the last month of my studying from a list I was making. If anyone can help, knows a hint, or easy way to do these problems and show me, I'd appreciate it. The problems are listed below with the answer the book gives in parenthesis. Thanks for all the help.
1.) .Jim can fill a pool carrying bucks of water in 30 minutes. Sue can do the same job in 45 minutes. Tony can do the same job in 1 ½ hours. How quickly can all three fill the pool together? (the answer is 15 minutes)
2.) ..If Steven can mix 20 drinks in 5 minutes, Sue can mix 20 drinks in 10 minutes, and Jack can mix 20 drinks in 15 minutes, how much time will it take all 3 of them working together to mix the 20 drinks? (the answer is 2m 44s)
3.) ..If Sam can do a job in 4 days that Lisa can do in 6 days and Tom can do in 2 days, how long would the job take if Sam, Lisa, and Tom worked together to complete it? (the answer is 1.09 days)
4.) A train traveled from Town A to Town B at an average speed of 48mph. The train returns from Town B to Town A along the same route at an average speed of 96mph. What was the average speed of the train, in mph, for the round trip? (book says 64mph)
5.) A committee of 2 people must be selected from a group of 16 people. In how many different ways may the committee be formed? (book says 120)
6.) There are 5 gold coins and 1 silver coin in a bag. If 2 coins are selected from this bag at random and without replacement, what is the probability that both coins are gold? (p = 2/3)
7.) Which of the following is 'x' equal to if y = (4x-5)/(3x+7)? [x = (7y+5)/(4-3y) ]
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1.) .Jim can fill a pool carrying bucks of water in 30 minutes. Sue can do the same job in 45 minutes. Tony can do the same job in 1 ½ hours. How quickly can all three fill the pool together? (the answer is 15 minutes)
2.) ..If Steven can mix 20 drinks in 5 minutes, Sue can mix 20 drinks in 10 minutes, and Jack can mix 20 drinks in 15 minutes, how much time will it take all 3 of them working together to mix the 20 drinks? (the answer is 2m 44s)
3.) ..If Sam can do a job in 4 days that Lisa can do in 6 days and Tom can do in 2 days, how long would the job take if Sam, Lisa, and Tom worked together to complete it? (the answer is 1.09 days)
4.) A train traveled from Town A to Town B at an average speed of 48mph. The train returns from Town B to Town A along the same route at an average speed of 96mph. What was the average speed of the train, in mph, for the round trip? (book says 64mph)
5.) A committee of 2 people must be selected from a group of 16 people. In how many different ways may the committee be formed? (book says 120)
6.) There are 5 gold coins and 1 silver coin in a bag. If 2 coins are selected from this bag at random and without replacement, what is the probability that both coins are gold? (p = 2/3)
7.) Which of the following is 'x' equal to if y = (4x-5)/(3x+7)? [x = (7y+5)/(4-3y) ]
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