A work can be completed by X men in 15 days. 10 more men join them after 3 days. The remaining work is now completed in 8 days. What is the value of X?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e 20
Concept Used :
Total work = Number of men × Number of days.
Given :
X men can do the work in 15 days.
(X + 10) men can do the work in 8 days.
Now the total work done by X men in 15 days = 15X
The work done by X men in 3 days = 3X
So, the remaining work to be done = 15X - 3X = 12X
Aso, 10 men joined after 3 days, so the number of men is X + 10.
Given that (X + 10) men can complete the remaining work in 8 days
i.e. (X + 10) × 8 = 12X
⇒ 8X + 80 = 12X
⇒ 4X = 80
⇒ X = 20.
Hence the value of X is 20.