Question

рабочий может выполнить всю работу за 2 часа ,а его ученик за 4 часа. за сколько они сделают все работу если будут работать совместно?

Answer 1

1)1:2=1/2 производительность рабочего
2)1:4=1/4 производительность ученика
3)1/2+1/4=3/4 совместная производительность
4)1:3/4=4/3 часа=1 час 20 мин
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Answer 2

Solving the Problem of Work Completion Time

To solve this problem, we can use the concept of work rate. The work rate is the amount of work done per unit of time. Let's denote the work rate of the worker as Ww and the work rate of the apprentice as Wa.

Given: - The worker can complete the entire work in 2 hours. - The apprentice can complete the entire work in 4 hours.

We can calculate their work rates as follows: - Worker's work rate: Ww = 1/2 (as the worker completes the work in 2 hours) - Apprentice's work rate: Wa = 1/4 (as the apprentice completes the work in 4 hours)

Combined Work Rate

When working together, their work rates are additive. Therefore, the combined work rate when they work together is: Wc = Ww + Wa = 1/2 + 1/4 = 3/4

Time to Complete the Work Together

To find the time it takes for them to complete the work together, we can use the formula: Time = Total Work / Combined Work Rate

Given that the total work is 1 (the entire work), we can calculate the time it takes for them to complete the work together: Time = 1 / (3/4) = 4/3 hours

So, when the worker and the apprentice work together, they will complete the entire work in 4/3 hours, which is approximately 1 hour and 20 minutes.

Therefore, when working together, they will complete all the work in approximately 1 hour and 20 minutes.