MathNet 2016-part-06 — 184 problems (EN–VI) Question 2

If $a$ and $b$ are positive integers such that $\frac{a}{b} = \frac{2}{3}$ and $a + b = 80$, then the product $ab$ is equal to

(A) 1 500 (B) 1 599 (C) 1 667 (D) 1 596 (E) 1 536