Question

11. A pipe can fill a cistern in 24 minutes and another pipe can fill
it in 30 minutes. But, a third pipe can empty it in 20 minutes.
V The first two pipes are kept open for 10 minutes in the
beginning and then the third pipe is also opened. In what time
is the cistern filled completely?
a) 10 min b) 20 min C) 37-min d) 15 min​

Answer 1

Answer:

ans. will be 20 minute.

Step-by-step explanation:

we will assume that total work will be lcm time taken by individual pipes

and efficiency will be calculated as ratio between work and time