4 men can check exam papers in 8 days working 5 hours regularly. What are the…
2025
4 men can check exam papers in 8 days working 5 hours regularly. What are the total hours 2 men should work in a day to check the double of the papers in 20 days?
- A.
6
- B.
7
- C.
8
- D.
9
Attempted by 626 students.
Show answer & explanation
Correct answer: C
Key idea: total work (in units) is proportional to number of men × days × hours per day (man-hours).
Work done in the first case = 4 men × 8 days × 5 hours/day = 160 man-hours.
Double the papers requires 2 × 160 = 320 man-hours.
Let x be the hours per day for 2 men working 20 days: 2 × 20 × x = 320 ⇒ x = 320 / 40 = 8 hours.
Answer: 8 hours per day.