Question

20. Two pipes A and B can fill a tank in 5 hours and 15 hours respectively. Initially, pipe A started filling the tank for 1 hour and then pipe B was also opened to fill the tank.
How much more time will these two pipes take to fill the remaining tank?​

Answer 1

Answer:

time to fill the remaining tank is 3 hours

Explanation:

part of tank filled by A in 1 hour

=1/5

part of tank filled by B in 1 hour

=1/15

part of tank filled by A & B in 1 hour

=4/15

volume of the remaining tank

=1-1/5

=4/5

4/5×x=4/15

x=4/15÷4/5

=4/15×5/4

=3 hours