Question

Two taps A and B can fill a bathtub in 10 minutes and 15 minutes respectively . If A was open for the first two minutes , B for the next two minutes and so on , the bathtub is filled in

Answer 1

Answer:

12 minutes

Step-by-step explanation:

Find the LCM of 10 and 15 = 30

ie, 30 parts are to be filled

Parts filled by A in a minute = 30/10 = 3

Parts filled by B in a minute = 30/15 = 2

Parts filled by A in two minutes = 2 * 3 = 6

Parts filled by B in a minute = 2 * 2 = 4

In 4 minutes, the fill 6 + 4 = 10 parts

So total time required = (30/10) * 4  = 3 * 4 = 12 minutes