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: The average of 4,8,12 and x is 10. Find the value of x?

Option A: 10

Option B: 16

Option C: 15

Option D: 24

Option E: 12
[A]: Option B

[Q]: Question: If x, y, and z are positive integers such that x is a factor of y and y is a factor of z, which of the following is NOT necessarily an integer?

Option A: (x + y

Option B: (y + z

Option C: yz/x

Option D: (2y + 3z

Option E: (xy + z
[A]: Option A

[Q]: Question: There are 13 South American countries, Anny has won a ticket to fly from Denver to one South American country and then directly to another South American Country before returning home to Denver again. Assuming there are four airports in each country, how many flights paths can Anny choose from?

Option A: 13.12.11.10.4.4.

Option B: 13.12.11.10.4

Option C: 13.12.4.4.

Option D: 13.12.4

Option E: 13.13.13.13
[A]:
Option C