Teaching BPSC बिहार माध्यमिक TGT (9 to 10) शिक्षक भर्ती 4.0 Mock Test Quantitative Aptitude Time and Work Pipe and Cistern
Two pipes A and B can fill the tank in 40 and 60 minutes, respectively. Both the pipes are opened together. After how many minutes should the pipe B be turned off, so that the tank be fill in 30 minutes?
1
20 min
2
15 min
3
28 min
4
More than one of the above
5
None of the above