Problem Solving

In a certain district, the ratio of the number of registered Republicans to the number of registered Democrats was \(\dfrac35.\) After \(600\) additional Republicans and \(500\) additional Democrats registered, the ratio was \(\dfrac45.\) After these registrations, there were how many more voters in the district registered as Democrats than as Republicans?

(A) 100
(B) 300
(C) 400
(D) 1,000
(E) 2,500

Answer: B

Source: Official Guide