Question 557116
Ramil can paint a fence in 4 hours, while Dino can do it in 5 hours. If they work together, what part of the fence can they paint in one hour? How long will it take them to finish painting the fence if they work together?
-------
Ramil rate: 1/4 job/hr
Dino rate: 1/5 job/hr
together rate: 1/x job/hr
-----
Equation:
rate + rate = together rate
1/4 + 1/5 = 1/x
5x + 4x = 20
9x = 20
Together rate: 1/x = 9/20 job/hr
----
Time to finish the job (11/20 th of the job)
---
Let "x" be amount of time to finish the job together.
x(20/9) = 21/20
x = 21/9 hrs = 2 1/3 hrs
===================================
Cheers,
Stan H.
===========