Question

A man can do a piece of work in 60 hours. If he takes his son with him and both work together then the work is finished in 40 hours. How many hours will the son take to do the same job, if he worked alone on the job?

Answer 1

Answer:I think answer will be 60

Answer 2

Answer:

Son will take 120 hours to complete the work if he worked alone

Step-by-step explanation:

given, the man can do a piece of work in 60 hours

then man's one hour work = $\frac{1}{60}$

If man and his son work together, then the work is finished in 40 hours

man+son one hour work = $\frac{1}{40}$

To find: number of hours required by son to complete the work, if he worked alone

Let x be the number the number of hours taken by son

Then, $\frac{1}{60}+\frac{1}{x}=\frac{1}{40}$

$\frac{60+x}{60x}=\frac{1}{40}$

40(60+x) = 60x

2(60+x) = 3x

120+2x = 3x

x = 120

Therefore, son will take 120 hours to complete the work if he worked alone