Pumps A, B, and C operate at their respective constant rates. Pumps A and B, operating simultaneously, can fill a certain tank in 2 hours; pumps A and C, operating simultaneously, can fill the tank in 3/2 hours; and pumps B and C, operating simultaneously, can fill the tank in 2 hours. How many hours does it take pumps A, B, and C, operating simultaneously, to fill the tank.
Choose the correct choice from the following options:
A) 1/3
B) 1/2
C) 1/4
D) 1
E) 5/6
A+B =2; A+1/4 =3/2 ,B+1/4 =2 ; ADD THEN 2*(A+B+1/4) = 4+3/2 = 11/2   A+B+1/4 = 11/4 HRS   1/4
<result>C</result>
Pumps A, B, and C operate at their respective constant rates. Pumps A and B, operating simultaneously, can fill a certain tank in 2 hours; pumps A and C, operating simultaneously, can fill the tank in 3/2 hours; and pumps B and C, operating simultaneously, can fill the tank in 2 hours. How many hours does it take pumps A, B, and C, operating simultaneously, to fill the tank.