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: The average age of 31 students in a group is 16 years. when teacher's age is included to it, the average increases by one.What is the teacher's age in years?

 Option A: 31

 Option B: 36

 Option C: 48

 Option D: 45

 Option E: 57
[EX A]: Option C

[EX Q]: Question: What is the next number of the following sequence
10, 7, 12, 10, 14, __ ?

 Option A: 13

 Option B: 14

 Option C: 15

 Option D: 16

 Option E: 17
[EX A]: Option A

[EX Q]: Question: A sum fetched a total simple interest of Rs. 4016.25 at the rate of 9 p.c.p.a. in 5 years. What is the sum?

 Option A: 8000

 Option B: 8925

 Option C: 8500

 Option D: 8700

 Option E: 8750
[EX A]:
Option B