Answer:
4 hours
Step-by-step explanation:
Part of the pool filled by first pipe in an hour = 1/6
Part of the pool filled by second pipe in an hour = 1/12
Part of the pool filled by first pipe and second pipe in an hour = 1/6 +1/12
[tex]=\frac{1*2}{6*2}+\frac{1}{12}\\= \frac{2}{12}+\frac{1}{12}\\\\=\frac{3}{12}\\\\=\frac{1}{4}[/tex]
Time taken by both the pipes to fill the pool = 4 hours