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.

[EX Q]: Question: A circular swimming pool is surrounded by a concrete wall 4 feet wide.if the area of the wall is 11/25 of the area of the pool, then the radius of the pool in feet is?

Option A: 22

Option B: 20

Option C: 9

Option D: 8

Option E: 1
[EX A]: Option B

[EX Q]: Question: The sum of the digits of a two-digit number is 15 and the difference between the digits is 3. What is the two-digit number?

Option A: 69

Option B: 78

Option C: 96

Option D: Cannot be determined

Option E: None of these
[EX A]: Option D

[EX Q]: Question: The functions f and g are defined for all the positive integers n by the following rule: f(n) is the number of perfect squares less than n and g(n) is the number of primes numbers less than n. If f(x) + g(x) = 16, then x is in the range:

Option A: 30 < x < 36

Option B: 30 < x < 37

Option C: 31 < x < 37

Option D: 31 < x < 38

Option E: 32 < x < 38
[EX A]:
Option C