# Difficult Time and Work Solved QuestionAptitude Discussion

 Q. There are four varieties of pipes Pipe $A$, Pipe $B$, Pipe $C$ and Pipe $D$. Each pipe can be either an inlet pipe or an outlet pipe but cannot be both. there are 5 tanks of equal volume. Tank $P$ is filled by Pipe $A$ and Pipe $B$ Tank $Q$ is filled by Pipe $A$ and Pipe $C$ Tank $R$ is filled by Pipe $A$ and Pipe $D$ Tank $S$ is filled by Pipe $B$ and Pipe $C$ Tank T is filled by Pipe $C$ and Pipe $D$ Time taken for the first 3 tanks ($P$, $Q$ and $R$) to get filled are in the ratio $1:2:4$ and the time taken for the $S$ and $T$ tanks to be filled are in the ratio $7:10$.  Find the outlet pipes among the 4 varieties.
 ✖ A. Pipes $C$ and $D$ ✖ B. Pipe $D$ ✖ C. Pipes $A$ and $B$ ✔ D. Pipe $A$

Solution:
Option(D) is correct

Let $A,B,C$ and $D$ do $a,b,c$ and $d$ with of work in an hour.

Let $A$ and $B$ fill the tank in 1 hour.