A large tanker can be filled by two pipes A and B in 60 and 40 minutes respectively. How many minutes will it take to fill the tanker from empty state if B is used for half the time and A and B fill it together for the other half?  Choose the correct choice from the following answers:  A) 65 min  B) 99 min  C) 56 min  D) 1Z min  E) 12 min
Part filled by (A + B) in 1 minute = (1/60 + 1/40) = 1/24   Suppose the tank is filled in x minutes.   Then, x/2(1/24 + 1/40) = 1   x/2 * 1/15 = 1 =&gt; x = 30 min.   Answer: 1Z min
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A large tanker can be filled by two pipes A and B in 60 and 40 minutes respectively. How many minutes will it take to fill the tanker from empty state if B is used for half the time and A and B fill it together for the other half?