SOLUTION: It takes joe 10 hours longer to do his math homework than it takes Tom because Tom comes to Ms. Wagners office for help. When Tom and Joe work together it takes them 12 hours to do
Algebra ->
Rate-of-work-word-problems
-> SOLUTION: It takes joe 10 hours longer to do his math homework than it takes Tom because Tom comes to Ms. Wagners office for help. When Tom and Joe work together it takes them 12 hours to do
Log On
Question 593189: It takes joe 10 hours longer to do his math homework than it takes Tom because Tom comes to Ms. Wagners office for help. When Tom and Joe work together it takes them 12 hours to do their homework. How long does it take Joe to do his homework alone? Answer by htmentor(1343) (Show Source):
You can put this solution on YOUR website! Let T = Tom's time
Then Joe's time = T + 10
Working together their work rate is 1/12, so we can write
1/T + 1/(T+10) = 1/12
((T+10) + T)/(T(T+10)) = 1/12
Simplify and solve:
T^2 - 14T - 120 = 0
Factor:
(T-20)(T+6) = 0
Take the positive solution, T=20
That means it takes Joe 30 hours to do his homework.
