three pipes A, B and C is attached too cistern . A can fill ut in 20 minutes and B can fill it in 30 minutes, C is a waste pipe, After opening both the pipe A and B , Riya leaves the cistern to fill and return when the cistern is supposed to be filled . But she found that waste pipe C had been left open , she close it and now the cistern takes 5 minutes more to fill. in how much time the pipe C can empty the full cistern?
Answers
Answered by
0
Answer:
Let pipe C alone can empty the cistern in x min.
A fills cistern in 1 min = 110
B fills cistern in 1 min = 115
A and B together fill in 1 min =10×1510+15=15025=6min
Since, waste pipe was left open for 6 min then,
6 min, 6x
part of cistern will be emptied by C
Now,
6x
part of the cistern would be filled by A and B in 2 min.
Hence,
cistern will be filled in 3x
min. And
x3
= 6
x = 18 min.
Similar questions