2013 · Q7
A mason can build a tank in 12 hours. After working for 6 hours, he took the help of a boy and finished the work in another 5 hours. The time that the boy will take alone to complete the work is
Elementary MathematicsArithmetic
- A30 hrs
- B45 hrs
- C60 hrs
- D64 hrs
Explanation
Mason does 6/12 + 5/12 = 11/12; boy does 1/12 in 5 hrs → 60 hrs alone. Answer C.