Three pumps running for eight hours a day may empty a tank in two days. To empty the tank in one day, how many hours must four pumps operate each day?
A. 9
B. 10
C. 11
D. 12
Answer:D
Three pumps running for eight hours a day may empty a tank in two days. To empty the tank in one day, how many hours must four pumps operate each day?
A. 9 B. 10 C. 11 D. 12
Explanation: Let x be the minimum number of working hours each day.Less working hours per day, more pumps (Indirect Proportion).There are fewer days in the week, but there are more hours in the day (Indirect Proportion).Days 1 : 2 Pumps 4 : 3 : 8 : ,3 x 2 x 8 = 4 x 1 x x,x = (3 x 2 x 8) x = (3 x 2 x 8) x = (3 x 2 x (4),x equals 12.