Banking Quantitative Aptitude Sample Paper Quantitative Aptitude Sample Paper-13

A and B can complete a piece of work in 18 days, B and C in 24 days and A and C in 36 days. In how many days, will all of them together complete the work?                                                          [NICL (AO) 2014]

A) 16

B) 15

C) 12

D) 10

E) 17

Correct Answer: A

Solution :

\[(A+B)'s\] one day work \[=\frac{1}{18}\] .(i)

\[(B+C)'s\]one day work \[=\frac{1}{24}\] .(ii)

and \[(A+C)'s\] one day works \[=\frac{1}{36}\] .(iii)

On adding Eqs. (i), (ii) and (iii), we get

\[2\,(A+B+C)=\frac{1}{18}+\frac{1}{24}+\frac{1}{36}\]

\[=\frac{4+3+2}{72}=\frac{9}{72}=\frac{1}{8}\]

\[\Rightarrow \] \[(A+B+C)'s\] one day work \[=\frac{1}{2\times 8}=\frac{1}{16}\]

So, A, B and C will together complete the work in

16 days.