18 men can do a piece of work in 20 days. After working for 8 days, they get a notice to complete the work 4 days earlier than originally scheduled. How many more men will be required to be hired to complete the work as per the new schedule?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 9
Let's first calculate the total work to be done. We can assume that the work is 1 unit for simplicity. So, 18 men can do 1 unit of work in 20 days, which means that the rate of work of one man is:
1/(18 × 20) = 1/360 units/day
After working for 8 days, the total work remaining is:
1 - (8/20) = 3/5 units
Now, they have to complete this remaining work in (20 - 8 - 4) = 8 days. Let's assume that x more men are required to complete this work in 8 days. So, the new total number of men will be (18 + x).
Using the formula for work, we can write:
(18 + x) × (1/360) × 8 = 3/5
Simplifying this equation, we get:
x = (3/5) × 360 × (5/8) - 18
x = 9