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: In a class of 40 students, 10 did not opt for math. 15 did not opt for science and 2 did not opt for either. How many students of the class opted for both math and science?

 Option A: 13

 Option B: 15

 Option C: 7

 Option D: 17

 Option E: 18

A: Option C
****
Q: 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

A: Option C
****
Q: Question: Of the eight participants in a certain competition, half are male, and half of the males are younger than 18 years of age. If half of the female competitors are also younger than 18 years of age, into how many distinct groups of 4 competitors could the participants be divided if each group must contain two males under 18 years of age and 2 females over 18 years of age?

 Option A: 1

 Option B: 4

 Option C: 6

 Option D: 9

 Option E: 20

A:
Option A
****