An author received $0.80 in royalties for each of the first 100,000 copies of her book sold and $0.60 in royalties for

[M7MBA]

An author received $0.80 in royalties for each of the first 100,000 copies of her book sold and $0.60 in royalties for each additional copy sold. If she received a total of $260,000 in royalties, how many copies of her book were sold?

(A) 130,000
(B) 300,000
(C) 380,000
(D) 400,000
(E) 420,000

Answer: D

Source: Official Guide