A certain automobile company’s best-selling model is the Speedster. The Speedster, like all of their other models, comes in coupe and convertible styles. 1/3 of the current inventory is Speedsters, of which 4/5 are convertibles. If there are 30 vehicles that are not Speedsters, how many Speedster convertibles are there? Choose the most appropriate option:
A) 13	B) 18	C) 12	D) 15	E) 17

Rationale: "total vehicle = 1 / 3 of speedster + 2 / 3 of others . speedster convertibles = 1 / 3 total vehicle * 4 / 5 given : 2 / 3 constitutes 30 vehicles . hence 1 / 3 constitutes 15 speedster convertibls = 15 * 4 / 5 = 12 c"
Answer: C