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: The total of the ages of Amar, Akbar and Anthony is 30 years. What was the total of their ages three years ago ?

 Option A: 20 years

 Option B: 28 years

 Option C: 71 years

 Option D: 21 years

 Option E: 31 years

A: Option D
****
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: A foreign language club at Washington Middle School consists of n students, 2/5 of whom are boys. All of the students in the club study exactly one foreign language. 1/3 of the girls in the club study Spanish and 3/4 of the remaining girls study French. If the rest of the girls in the club study German, how many girls in the club, in terms of n, study German?

 Option A: 2n/5

 Option B: n/3

 Option C: n/5

 Option D: 2n/15

 Option E: n/10

A:
Option E
****