Question

Q23. Two pipes a and b can separately fill a cistern in 60 min and 75 min respectively. There is a third pipe in the bottom of the cistern to empty it. If all the three pipes are simultaneously opened, then the cistern is full in 50 min. In how much time, the third pipe alone can empty the cistern ?

Answer 1

Answer:

20 second time taken the pipe

Answer 2

Answer:

Step-by-step explanation:

a can fill cistern in 60 mins

in 1 min a can fill 1/60 part of cistern

b can fill cistern in 75 mins

in 1 min b can fill 1/75 part of cistern

let third pipe c can empty cistern in x mins

then in 1 min c can empty 1/x part of cistern

all of them can fill it in 50 min

in 1 min they can fill 1/50 part of cistern

then,

1/60 + 1/75 -1/x= 1/50

1/x= 1/60 +1/75 -1/50

1/x=(5+4-6)/300

1/x=3/300=1/100

1/x=1/100

x=100

third pipe can empty cistern in 100 mins