2023 · Q8
A can do certain work at twice the speed of B. Further, B can do the same work at 1.5 times the speed of C. All of them together can finish the work in 12 days. In how many days can C alone finish the work?
Elementary MathematicsTime and Work
- A36 days
- B45 days
- C60 days
- D66 days
Explanation
Let C's rate be r; then B works at 1.5r and A at 2 × 1.5r = 3r, for a combined rate of 5.5r. Finishing together in 12 days gives 5.5r × 12 = 1 whole work, so r = 1/66. C alone therefore needs 66 days (D).