TASK DEFINITION: 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.
PROBLEM: 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

SOLUTION: Option C

PROBLEM: Question: Which of the following is NOT a factor of 10! ?

 Option A: 1440

 Option B: 625

 Option C: 160

 Option D: 80

 Option E: 50

SOLUTION: Option B

PROBLEM: Question: A mixture of 150 liters of wine and water contains 20% water. How much more water should be added so that water becomes 25% of the new mixture?

 Option A: 10 liters

 Option B: 11 liters

 Option C: 18 liters

 Option D: 19 liters

 Option E: 12 liters

SOLUTION:
Option A