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.

Q: How many minutes did John take, driving at 20 miles per hour, to go the same distance that Mary took 30 minutes to drive at 60 miles per hour?
(A)10 (B)30 (C)60 (D)90 (E)180

A: D
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Q: If it takes a people 10 hours to finish a certain task, how many would it take for \(a^2\) people to finish the same task?
(A)5 (B)10 (C)\(\frac { 5 } { a } \) (D)\(\frac { 10 } { a } \) (E)\(\frac { a } { 10 } \)

A: D
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Q: If, at a certain clothing store, three pairs of dress socks and four pairs of athletic socks cost a total of \$27 and four pairs of dress socks and three pairs of athletic socks cost a total of \$29, what is the combined cost of one pair of dress socks and one pair of athletic socks?
(A)\$26 (B)\$28 (C)\$16 (D)\$8 (E)\$2

A:
D
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