Three pipes of same capacity can fill a tank in 12 hours. If there are only two pipes of same capacity, the tank can be filled in?
Choose the correct choice from the following:
A) 18 B) 8 C) 12 D) 6 E) 4
The part of the tank filled by three pipes in one hour   = 1/12   =&gt; The part of the tank filled by two pipes in 1 hour   = 2/3 * 1/12 = 1/18.   The tank can be filled in 18 hours.   18nswer:18
<result>A</result>
Three pipes of same capacity can fill a tank in 12 hours. If there are only two pipes of same capacity, the tank can be filled in?