3 men or 15 boys can do a piece of work in 30 days. In how many days will 2 men and 5 boys do this work?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 30 days
Since 3 men and 15 boys each finish the same work in the same 30 days, 3 men do as much work as 15 boys. Turning the men into boys puts the whole group in one unit.
3 men \(=\) 15 boys, so 1 man \(=\) 5 boys
2 men and 5 boys \(=10+5=15\) boys
15 boys finish the work in 30 days (given), so 2 men and 5 boys also take 30 days