Question

If Jim Roller can paint a room in 3 hours while John Brush would take 5 hours, how long will they take if they work together? 1/8 hour

Answer 1

Your answer is 1 7/8. Hope this helps!

Answer 2

Answer:
`1(7)/(8)\ hours`

Explanation:

If they are working alone

Jim does of the job in 1 hour=
`(1)/(3)` of work

John does of the job in 1 hour=
`(1)/(5)` of work

Let x be the number of hours to do the job if they work together.

Thus, each hour, they do
`(1)/(x)` of the job when they work together.

According to the question,

`(1)/(x)=(1)/(3)+(1)/(5)`

`\Rightarrow(1)/(x)=(5+3)/(15)\\\Rightarrow(1)/(x)=(8)/(15)\\\Rightarrow\ x=(15)/(8)=1(7)/(8)\ hours`

∴ The number of hours to do the job if they work together=
`1(7)/(8)\ hours`