RRB Paramedical Staff Nurse Model Paper 1

Time taken by A and B together to complete work $=8$ days
Time taken by B alone to complete work $=12$ days
Time taken by C alone to complete work $=12$ days
Now take LCM of 8, 12 and 12
LCM $\left(8,12,12\right)=24$
Assume total work $=24$ unit
Efficiency of (A+B) together $=\frac{24}{8}=3$ unit/day
Efficiency of B = 2 unit/day & Efficiency of C = 2 unit/day
4 days' works of A and $\mathrm{B}=4\times 3=12$ unit
2 days' works of $\mathrm{B}=4$ unit
Remaining work $=24$ unit $-\left(12+4\right)$ unit $=8$ unit
Days required for $\mathit{C}$ to complete the remaining work days