Question

Три человека могут выполнить работу за 15 часов.За какое время могут выполнить ту же работу девять человек?

Answer 1

3*15 = 45
45 / 9 = 5 часов

Answer 2

Calculation of Time Required for Nine People to Complete the Same Task

To determine the time required for nine people to complete the same task, we can use the concept of work done.

Given that three people can complete the task in 15 hours, we can assume that the work done by these three people is equal to the total work required for the task. Therefore, we can calculate the work done by three people as follows:

Work done by three people = 1 task

Now, let's calculate the work done by each person in one hour:

Work done by one person in one hour = 1 task / 15 hours = 1/15 task per hour

Since we know the work done by one person in one hour, we can calculate the total work done by nine people in one hour:

Work done by nine people in one hour = (1/15 task per hour) * 9 people = 9/15 task per hour

To find the time required for nine people to complete the task, we need to calculate the reciprocal of the work done by nine people in one hour:

Time required for nine people to complete the task = 1 / (9/15 task per hour)

Simplifying the expression, we get:

Time required for nine people to complete the task = 15/9 hours

Therefore, nine people can complete the same task in 15/9 hours, which is approximately 1.67 hours.

Please note that this calculation assumes that the work is evenly distributed among the people and that there are no other factors affecting the completion time.