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: If the average (arithmetic mean) of 18 consecutive odd integers is 414, then the least of these integers is

 Option A: a

 Option B: b

 Option C: c

 Option D: d

 Option E: e
[EX A]: Option A

[EX Q]: Question: The average runs scored by a batsman in 20 matches is 40. In the next 10 matches the batsman scored an average of 20 runs. Find his average in all the 30 matches?

 Option A: 31

 Option B: 46

 Option C: 88

 Option D: 33.33

 Option E: 12
[EX A]: Option D

[EX Q]: Question: In 1986 the book value of a certain car was 2/3 of the original price, and in 1988 its book value was 1/2 of the original purchase price. By what percent did the book value for this car decrease from 1986 to 1988?

 Option A: 16 2/3 %

 Option B: 25 percent

 Option C: 33 1/3 %

 Option D: 50%

 Option E: 75%
[EX A]:
Option B