A and B together can complete a work in 12 days. B and C together can complete…
2025
A and B together can complete a work in 12 days. B and C together can complete the same work in 15 days.
C and A together can do it in 20 days. In how many days can A alone complete the job?
- A.
30 days
- B.
20 days
- C.
50 days
- D.
15 days
Attempted by 4 students.
Show answer & explanation
Correct answer: A
Let rates of A, B, and C be a, b, and c. Then a+b=1/12, b+c=1/15, and c+a=1/20. Adding gives 2(a+b+c)=1/5, so a+b+c=1/10. Therefore a = 1/10 - 1/15 = 1/30, so A alone takes 30 days.