2012 · Q13
A and B can do a piece of work in 10 hours. B and C can do it in 15 hours, while A and C take 12 hours to complete the work. B independently can complete the work in:
Elementary MathematicsArithmetic
- A12 hours
- B16 hours
- C20 hours
- D24 hours
Explanation
Adding the three rates: 2(a+b+c) = 1/4, so b = 1/8 - 1/12 = 1/24, i.e. 24 hours alone.