Pipe A and B running together can fill a cistern in 6 minutes. If B takes 5 minutes more than A to fill the cistern then the times in which A and B will fill the cistern separately will be, respectively:

Let pipe A fills the cistern in x minutes. 

Therefore, pipe B will fill the cistern in$(x + 5)$ minutes.

Now,

$$\begin{gathered} \frac{1}{\mathrm{x}}+\frac{1}{\mathrm{x}+5}=\frac{1}{6} \\ \Rightarrow x=10 \end{gathered}$$

Thus, the pipes A and B can fill the cistern in 10 minutes and 15 minutes, respectively