A can do as much work as B and C together can do. A and B together can do a piece of work in 9 hours and 36 minutes and C can do it in 48 hours. The time (in hours) that B need to do the work alone is:
Answer & explanation
Correct answer: option 3
ATQ, Efficiency ratio:
A : B + C = 1 : 1 = 2R .......(i)
A + B : C
Time : 9\(\frac{3}{5}\) : 48
Time : \(\frac{48}{5}\) : 48
Time : 1 : 5
Effic. : 5 : 1 = 6 ......(ii)
(i) × 3 (to make (i) and (ii) equal)
⇒ A : (B + C) = 3 : 3 &
⇒ A + B : C = 5 : 1
Here, we can calculate:
A : B : C = 3 : 2 : 1
Now,
C can do the work in 48 hours, means total work = 48 × 1 = 48
B will do it in = \(\frac{48}{2}\) = 24hrs