Two hoses together fill a pool in 2 h. If only hose A is used, the pool fills in 3 h. How long would it take to fill the pool if only hose B were used?

Question

I multiplied 3 and 2 and got 6 hours.

Is this a valid method?

Thanks

Answer 1

nope. consider the fraction of the job done in one hour:

1/3 + 1/b = 1/2

In this case you got lucky, since indeed 1/3 + 1/6 = 1/2.

Answer 2

Thanks!