RRB Junior Engineer Stage 1 Model Papers 8

9 hours 36 minutes $=9+\frac{36}{60}+9\frac{3}{5}\mathrm{hours}=\frac{48}{5}\mathrm{hours}$
(A+B)'s 1 hour's work $=\frac{5}{48}\mathrm{hours}$
C's 1 hour's work $=\frac{1}{48}$
(A+B+C)'s 1 hour's work $=\frac{5}{48}+\frac{1}{48}=\frac{1}{8}$....(i)
A's 1 hours work =(B+C)'s 1 hour's work .....(ii)
$2\times \mathit{A}\prime \mathit{s}$ 1 hour's work $=\frac{1}{8}$
A's 1 hour's work $=\frac{1}{16}$
∴ B's 1 hour's work $=\frac{5}{48}-\frac{1}{16}=\frac{5-3}{48}=\frac{1}{24}$
∴ B alone will finish the work in 24 hours