You are given a mathematical question described with an open-ended vocabulary. Questions in this task involve real-world situations, describing a mathematical problem. You are also given 4 or 5 answer options (associated with "A", "B", "C", "D", "E"). Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D', 'E'. LaTeX mathematical format (the standard way to express mathematical expressions in the typesetting software known as LaTeX) is used to express equations. Each question is solvable with high school math knowledge. Give only one answer for each question.

Let me give you an example: John has y dollars to spend on some new CDs from Music Plus, an online record store. He can buy any CDs at the members' price of x dollars each. To be a member, John has to pay a one-time fee of $19. Which of the following expressions represents the number of CDs John can purchase from Music Plus?
(A)\(\frac{xy}{19}\) (B)\(\frac{y + 19}{x}\) (C)\(\frac{2y - x}{19}\) (D)\(\frac{y - 19}{x}\) (E)\(\frac{19 - x}{y}\)
The answer to this example can be: D
Here is why: john must pay 19 dollar to buy a membership then he will have \(y-19\) dollar remaining so he can buy \(rac{y - 19}{x}\) CDs.

OK. solve this:
If it takes 10 people 18 hours to do a certain job, how many hours would it take 15 people, working at the same rate, to do \(\frac { 2 } { 3 } \) of the same job?
(A)6 (B)8 (C)9 (D)10 (E)12
Answer:
B