RRB Paramedical Staff Nurse Model Paper 7

First man's 1 day's work $=\frac{1}{7}$
Second man's 1 day's work $=\frac{1}{8}$
Let boy's 1 day's work $=\frac{1}{\mathit{x}}$
According to the question,
$\frac{1}{7}+\frac{1}{8}+\frac{1}{\mathit{x}}=\frac{1}{3}$
$\Rightarrow \frac{1}{\mathit{x}}=\frac{1}{3}-\frac{1}{7}-\frac{1}{8}$
$=\frac{56-24-21}{168}$
$=\frac{11}{168}$
Thus, ratio is their one day's work
$=\frac{1}{7}:\frac{1}{8}:\frac{11}{168}$
$=24:21:11$ (taking LCM)
Sum of the ratios
$=24+21+11=56$
Thus Boy's share in wages
$=\frac{11}{56}\times 1400=\mathrm{Rs}275$