3 pumps, working 8 hours a day, can empty a tank in 2 days. How many hours a day must 4 pumps work to empty the tank in 1 day?
Choose the correct choice from the following options:  A) 12  B) 9  C) 14  D) 11  E) 16
Let the required number of working hours per day be x.   More pumps, Less working hours per day (Indirect Proportion)   Less days, More working hours per day (Indirect Proportion)   Pumps	4:3 :: 8 : x   Days 1:2   :.4 * 1 * x = 3 x 2 x 8   x =	(3 x 2 x 8)/(4)   x = 12.   12nswer is 12.
<result>A</result>
3 pumps, working 8 hours a day, can empty a tank in 2 days. How many hours a day must 4 pumps work to empty the tank in 1 day?