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.

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
Option C

Question: In how many different number of ways a Committee of 3 person of can be selected from 5 boys and 3 girls such that at least 1 girl is included in the committee

 Option A: 41

 Option B: 42

 Option C: 46

 Option D: 48

 Option E: 50
Option C

Question: Two trains 190 m and 160 m long run at the speed of 60 km/hr and 40 km/hr respectively in opposite directions on parallel tracks. The time which they take to cross each other is?

 Option A: 10.6 sec

 Option B: 18.8 sec

 Option C: 14.6 sec

 Option D: 10.8 sec

 Option E: 12.6 sec

Option E