Question

Человек выполняет работу за 14 дней. Если он будет работать вместе с сыном, то работа будет выполнена за 10 дней. За сколько дней эту работу выполнит сын?

Answer 1

1)14-10=4(д) - с сыном
2)14+4=18(д)
ответ за 18 дней сын выполнит всю работу)

Answer 2

Solution

To solve this problem, we can use the concept of "work done" and "work rate." Let's denote the work to be done as W and the work rate of the person as R. The work done by the person working alone for 14 days is 14R, and the work done by the person and his son working together for 10 days is 10(R + S), where S is the work rate of the son.

We can set up the following equation based on the given information:

14R = 10(R + S)

We need to solve for S, which represents the work rate of the son.

Calculation

To solve for S, we can first simplify the equation:

14R = 10R + 10S

Subtracting 10R from both sides gives:

4R = 10S

Now, we can solve for S:

S = (4/10)R

This means that the son's work rate is 40% of the father's work rate.

Conclusion

Therefore, if the father completes the work in 14 days, the son, working at 40% of the father's rate, will complete the same work in 35 days.