Question

two pipes a and B can separately fill a tank in 10 and 15 minutes respectively. a person opens both the pipes together, when the tank should have been full, he finds the drain pipe was open. he then closes the drainpipe, in another 4 minutes the tank was full. how much time is required for the waste pipe to empty the tank when it is full?​

Answer 1

$\huge\red{A}\pink{N}\orange{S} \green{W}\blue{E}\gray{R} =$

1/10 + 1/15 = 1/6 x 3 = 1/2

1 - 1/2 = 1/2

1/10 + 1/15 - 1/x = 1/2

x = 8.57 min

Answer 2

Answer:

1/10 + 1/15 = 1/6 x 3 = 1/2

1 - 1/2 = 1/2

1/10 + 1/15 - 1/x = 1/2

x = 8.57 min.

$thanks$