Problem Solving

Mr. Kramer, the losing candidate in a two-candidate election, received 942,568 votes, which was exactly 40 percent of all the votes cast. Approximately what percent of the remaining votes would he need to have received in order to have won at least 50 percent of all the votes cast?

(A) 10%
(B) 12%
(C) 15%
(D) 17%
(E) 20%

The answer is D

What is the best and quickest way to solve this one?

Let T be the total Vote
X = the percentage of rem votes to produce 50% votes
0.4T + X(0.6T) = 0.5T

Solve for x, Aprox 17%