SOLUTION: Working alone Ann can clean the house in 7 hours. WOrking with Tom they can clean it in 4 hours. How long will it take Tom to clean the house alone?

Algebra ->  Expressions-with-variables -> SOLUTION: Working alone Ann can clean the house in 7 hours. WOrking with Tom they can clean it in 4 hours. How long will it take Tom to clean the house alone?      Log On


   



Question 461969: Working alone Ann can clean the house in 7 hours. WOrking with Tom they can clean it in 4 hours. How long will it take Tom to clean the house alone?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Working alone Ann can clean the house in 7 hours.
---
Ann's rate = 1/7 job/hr
-------------------------------
WOrking with Tom they can clean it in 4 hours.
Together rate = 1/4 job/hr
-------------------------------
How long will it take Tom to clean the house alone?
Tom's rate = 1/x job/hr
=================================
Equation:
rate + rate = together rate
1/7 + 1/x = 1/4
4x + 28 = 7x
3x = 28
x = 28/3 hrs = 9 1/3 hrs = 9 hrs 20 minutes (Tom's time to do job alone)
==============
Cheers,
Stan H.
==============