Three men do as much work as 4 boys do in 21 days. In how many days will 9 men and 2 boys complete the same work?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 6.
Let total work = LCM of 63 & 84 = 252 units
3 men = 4 boys ⇒ 252 units in 21 days ⇒ 12 units/day
1 man = 4 units/day, 1 boy = 3 units/day
Now, 9 men + 2 boys = 9×4 + 2×3 = 36 + 6 = 42 units/day
Days = 252 / 42 = 6 days