Cryptography Interview Question:

Pipe A can fill in 20 minutes and Pipe B in 30 mins and Pipe C can empty the same in 40 mins.If all of them work together, find the time
taken to fill the tank?

Submitted by: Administrator

a fill - 1/20 per minute
b fill - 1/30 per minute
c can empty - 1/40 per minute


Suppose this take x minute

1 x +1x - 1x
--- -- ---- =1
20 30 40

Solve this x=17(approximately)
Submitted by: Administrator