A group of men decided to complete a job in 4 days. However, since 10 men dropped out every day, the job got completed at the end of the 7th day. How many men were there in the beginning?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 70.
Let total work = W
Let the initial number of men = x
Work done each day:
Day 1: x men
Day 2: x − 10
Day 3: x − 20
Day 4: x − 30
Day 5: x − 40
Day 6: x − 50
Day 7: x − 60
Total work = x + (x - 10) + (x - 20) + (x - 30) + (x - 40) + (x - 550) + (x - 60)
Total work = 7x - 210
Given: originally planned to finish in 4 days ⇒ daily work = W/4
So, total work = 4 × x = 4x
⇒ 7x - 210 = 4x
⇒ 3x = 210
⇒ x = 70