Reservoir \(A\) contains \(450\) million gallons of water more than does Reservoir \(B.\) If \(100\) million gallons of

[M7MBA]

Reservoir \(A\) contains \(450\) million gallons of water more than does Reservoir \(B.\) If \(100\) million gallons of water were to be drained from Reservoir \(A\) into Reservoir \(B,\) then Reservoir \(A\) would contain twice as much water as would Reservoir \(B.\) How many million gallons of water does Reservoir \(A\) currently contain?

A. 500
B. 600
C. 700
D. 800
E. 900

Answer: B

Source: Princeton Review

[Scott@TargetTestPrep]

Reservoir \(A\) contains \(450\) million gallons of water more than does Reservoir \(B.\) If \(100\) million gallons of water were to be drained from Reservoir \(A\) into Reservoir \(B,\) then Reservoir \(A\) would contain twice as much water as would Reservoir \(B.\) How many million gallons of water does Reservoir \(A\) currently contain?

A. 500
B. 600
C. 700
D. 800
E. 900

Answer: B

Solution:

We can create the equations:

A = 450 + B

and

A - 100 = 2(B + 100)

A - 100 = 2B + 200

A = 2B + 300

Substituting, we have:

450 + B = 2B + 300

150 = B

So A = 450 + 150 = 600.

Answer: B