Question

Bob can paint a fence in 5 hours, and working with Jen, the two of them painted a fence in 2 hours. How long would it have taken Jen to paint the fence alone?

Answer 1

Answer:
`(10)/(3)`

Explanation:

Given

Bob can Paint a fence in 5 hr

so full job can be done in 5 hr

in 1 hr
`(1)/(5)` job is done

suppose Jen done the work in x hr

so in 1 hr
`(1)/(x)` part of job is done

Also if they combine they can do the job in 2 hr

so in 1 hr
`(1)/(2)`

so
`(1)/(5)+(1)/(x)=(1)/(2)`

`(1)/(x)=(1)/(2)-(1)/(5)`

`(1)/(x)=(5-2)/(10)`

`x=(10)/(3) hr`