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?

Question

days hours

Answer 1

Jim's rate --- 1/5
dad's rate --- 1/x

combined rate = 1/5 + 1/x
= (x+5)/(5x)

given: (x+5)/(5x) = 1/2
5x = 2x + 10
3x = 10
x = 10/3

so by himself dad could build it in 3 1/3 days

Answer 2

I posted the above reply yesterday to this same question.

You just cut-and-pasted my answer word for word and made it your own.
Not cool!

Answer 3

in two days, Jim does 2/5 of the job, so his dad does 3/5

3/5 in two days means 5/5 (the whole thing) in ... 2 * 5/3 days

Answer 4

@Reiny my apologies, I did copy and paste

Answer 5

T1 = 5 days = Jim's time.
T2 = Father's time.

T1*T2(T1+T2) = 2.
5*T2/(5+T2) = 2,
5T2 = 10+2T2,
T2 = 3 1/3.

Answer 6

Thanks all of you