40 men can do certain work in 25 days. After 10 days 25 men left. Find the number of days in which the remaining work is completed?

A)20 days      B)40 days C)15 days D)25 days

Ans:B)40 days

 Given:

40 men can complete a certain work in 25 days.

After 10 days, 25 men left.

Let's break down the problem into steps:

Step 1: Calculate the Total Work:

Let the total work be represented by ( W ).

40 men can complete the work in 25 days, so the total work is completed in ( 40 \times 25 = 1000 ) man-days.

Step 2: Work Done in 10 Days:

In 10 days, 40 men complete ( 40 \times 10 = 400 ) man-days of work.

Step 3: Work Remaining:

After 10 days, 25 men left, so the remaining men working are 40 - 25 = 15 men.

Work remaining after 10 days = Total work - Work done in 10 days = 1000 - 400 = 600 man-days.

Step 4: Calculate the Number of Days to Complete the Remaining Work:

The remaining work of 600 man-days will be completed by 15 men.

Number of days to complete the remaining work = Remaining work / (Men working * Days) = 600 / (15 * x), where x is the number of days.

Step 5: Solve for x:

( 600 = 15x )

( x = 600 / 15 = 40 )

Therefore, the number of days in which the remaining work is completed is 40 days (Option B).