Three pipes of same capacity can fill a tank in 8 hours. If there are only two pipes of same capacity, the tank can be filled in.	Select:
A) 17 hours B) 12 hours C) 16 hours D) 24 hours E) None of these
Explanation:   The part of the tank filled by three pipes in one hour = 1/8   =&gt; The part of the tank filled by two pipes in 1 hour = 2/3 * 1/8 = 1/12.   The tank can be filled in 12 hours.   ANSWER IS 12 hours
<result>B</result>
Three pipes of same capacity can fill a tank in 8 hours. If there are only two pipes of same capacity, the tank can be filled in.