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:

24

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