Question

If a pipe a fills a tank in 10 hours and a pipe b fills it in 15 hours, then the tank will be filled by a and b together in how much time?

Answer 1

10x15. 150
-------- = --------- =6 ans
10+15. 25

Answer 2

together=1/10+1/15
we have reciprocal them
LCM=30
=3+2/30
=5/30
simplify them
and reciprocal the answer
you will get 1/6 after reciprocal you will get 6hours