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

Answer:

$3\frac{1}{3}\ days$

Step-by-step 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

$\frac{100\%}{5}=\frac{x}{2}\\\\x=100(2)/5\\\\x= 40\%$

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

$\frac{2}{60}\frac{days}{\%}=\frac{x}{100}\frac{days}{\%}\\\\x=100(2)/60\\\\x=\frac{10}{3}\ days$

Convert to mixed number

$\frac{10}{3}\ days=\frac{9}{3}+\frac{1}{3}=3\frac{1}{3}\ days$