You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.

[Q]: Question: If x and y are negative integers, which of the following statements must be true?
I. (-x)^y is positive.
II. (-x)^(-y) is positive.
III. x^(-y) is positive.

 Option A: None

 Option B: II only

 Option C: I and II

 Option D: I and III

 Option E: I, II and III
[A]: Option C


[Q]: Question: Car X began traveling at an average speed of 35 miles per hour. After 72 minutes, car Y began traveling at an average speed of 41 miles per hour. When both cars had traveled the same distance, both cars stopped. How many miles did car X travel from the time car Y began traveling until both cars stopped?

 Option A: 140

 Option B: 175

 Option C: 210

 Option D: 245

 Option E: 280
[A]: Option D


[Q]: Question: The mean proportional between 4 and 9 is?

 Option A: 21

 Option B: 35

 Option C: 44

 Option D: 12

 Option E: 11
[A]:
Option B