Question

A carpenter can do a job in two hours. His assistant can do the same job in three hours. How long would it take them to do the job together?PLZ HELP

Answer 1

Answer:
`1(1)/(5)\text{ hours}`

Explanation:

Given : A carpenter can do a job in two hours.

i.e. rate of work done by carpenter per hour=
`(1)/(2)` (1)

Also, His assistant can do the same job in three hours.

i.e. rate of work done by assistant per hour=
`(1)/(3)` (2)

Let t be the time taken by both of them if they work together , then we have

`(1)/(t)=(1)/(2)+(1)/(3)` [Adding (1) and (2)]

`\Rihtarrow\ (1)/(t)=(3+2)/(6)=(5)/(6)\\\\\Rightarrow\ t=(6)/(5)\text{ hour}\\\\\Rightarrow\ t=(6)/(5)=1(1)/(5)\text{ hours}`

Hence, it would take
`1(1)/(5)\text{ hours}` to them to do the job together.