Problem Statement:
If 15 men can complete a work in 20 days, we need to find out how many days it will take for 5 men to complete the same work.

Solution:

We can solve this problem using the concept of man-days, which is the product of the number of men and the number of days taken to complete a work.

Let's calculate the man-days required to complete the work with 15 men in 20 days:
Man-days = Number of men × Number of days
Man-days = 15 × 20
Man-days = 300

Calculation for 5 Men:
Now, we need to find out how many days it will take for 5 men to complete the same work. Let's assume it takes x days for 5 men to complete the work.

Man-days = Number of men × Number of days
300 = 5 × x
300 = 5x

To find the value of x, we need to divide both sides of the equation by 5:
300/5 = 5x/5
60 = x

Therefore, it will take 5 men 60 days to complete the same work.

Explanation:
- We are given that 15 men can complete a work in 20 days, which means they can complete 300 man-days of work.
- To find out how many days it will take for 5 men to complete the same work, we can use the concept of man-days.
- Man-days is calculated by multiplying the number of men by the number of days taken to complete a work.
- We can set up an equation using the man-days for 15 men and solve for the number of days for 5 men.
- By dividing both sides of the equation by 5, we find that it will take 5 men 60 days to complete the same work.
- Therefore, the answer to the problem is 60 days.

Final Answer:
It will take 5 men 60 days to complete the same work.