2014 · Q5
A is thrice as efficient as B and hence completes a work in 40 days less than the number of days taken by B. What will be the number of days taken by both of them when working together?
Elementary MathematicsTime and Work
- A22.5 days
- B15 days
- C20 days
- D18 days
Explanation
If A takes x days, B takes 3x days and 3x − x = 40 gives x = 20. Together: 1/20 + 1/60 = 1/15, so 15 days.