Question

Jim and his dad are bricklayers. Jim can lay bricks for a fireplace and chimney in 5 days. With his father's help he can build it in 2 days. How long would it take his father to build it alone?

Answer 1

3 1/3

Explanation:

Answer 2

`3(1)/(3)\ days`

Explanation:

we know that

Jim can do the work in 5 days

so

The 100% of the work in 5 days

by proportion

Find out how much can do in 2 days

Let

x ----> the percentage of the work in 2 days

`(100\%)/(5)=(x)/(2)\\\\x=100(2)/5\\\\x= 40\%`

Remember that

Jim and his dad can do the work in 2 days

so

The 100% of the work in 2 days

Jim in 2 days can do 40% of the work

therefore

His dad in 2 days can do (100%-40%)=60%

by proportion

Find out how long would it take his father to build it alone

Let

x -----> the time it take his father to build it alone

`(2)/(60)(days)/(\%)=(x)/(100)(days)/(\%)\\\\x=100(2)/60\\\\x=(10)/(3)\ days`

Convert to mixed number

`(10)/(3)\ days=(9)/(3)+(1)/(3)=3(1)/(3)\ days`