Question

Двое рабочих, работая вместе, могут выполнить некоторую работу за 6 часов. Один из них, работая самостоятельно, может выполнить эту работу за 15 часов. За сколько часов ее может выполнить самостоятельно другой рабочий?

Answer 1

6:2=3 
15:3=5
Ответ за 5 часов мот выполнить эту работу второй рабочий 

Answer 2

Problem Analysis

We are given that two workers can complete a certain task together in 6 hours, and one of the workers can complete the task alone in 15 hours. We need to determine how many hours the other worker would take to complete the task alone.

Solution

Let's assume that the first worker's rate of work is represented by x (in terms of the fraction of the task completed per hour) and the second worker's rate of work is represented by y.

From the given information, we know that when they work together, they can complete the task in 6 hours. This means that their combined rate of work is 1/6 of the task per hour.

We also know that the first worker can complete the task alone in 15 hours. This means that the first worker's rate of work is 1/15 of the task per hour.

To find the second worker's rate of work, we can subtract the first worker's rate from the combined rate: y = 1/6 - 1/15

Now, we can solve for y to find the second worker's rate of work.

Calculation

Let's calculate the value of y:

y = 1/6 - 1/15

Simplifying the expression: y = (5/30) - (2/30) y = 3/30 y = 1/10

This means that the second worker's rate of work is 1/10 of the task per hour.

To find the number of hours it would take for the second worker to complete the task alone, we can use the formula: Time = 1 / Rate

Substituting the value of y into the formula: Time = 1 / (1/10) Time = 10 hours

Therefore, the second worker can complete the task alone in 10 hours.

Answer

The second worker can complete the task alone in 10 hours.