RRB Paramedical Staff Nurse Model Paper 3

Given, Time taken by $(A+B)$ to fill the tank $=6h$ Thus, part of tank filled by A + B in $1h=\frac{1}{6}$ ..... (i)(if a pipe fills a tank in $x$ h, then the part of tank filled in $1h=\frac{1}{x}$) Similarly, part of tank filled by (B + C) in $1h$. $=\frac{1}{10}$.....(ii) And part of tank filled by (C + A) in $1h=\frac{2}{15}$......(iii) Now, part of tank filled by (A + B + C) in $1h$ On adding Esq. (i), (ii), (in), we get $A+B+B+C+C+A$ $=\frac{1}{6}+\frac{1}{10}+\frac{2}{15}$ $\Rightarrow 2A+2B+2C=\frac{5+3+4}{30}$ $\Rightarrow 2(A+B+C)=\frac{12}{30}$ $\Rightarrow (A+B+C)=\frac{12}{60}$ $\Rightarrow (A+B+C)=\frac{1}{5}$ Hence, A, B and C all three can fill the tank in 5h (if a pipe fills $\frac{1}{x}$ part of the tank in $1h$, then the time taken by the pipe to fill the full tank $=xh$ )