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: Kim has 3 pairs of shoes; each pair is a different color. If Kim randomly selects 2 shoes without replacement from the 6 shoes, what is the probability that she will select 2 shoes of the same color?

Option A: 2/5

Option B: 1/5

Option C: 1/9

Option D: 1/10

Option E: 1/25
[EX A]: Option B

[EX Q]: Question: For any positive integer Y, the sum of the first Y positive integers equals Y(Y+1)/2 . If X and Y are positive integers and X > Y, what is the sum of all the integers between X and Y, inclusive?

Option A: X(X+1

Option B: X(X+1

Option C: X(X+1

Option D: X(X+1

Option E: X(Y+1
[EX A]: Option B

[EX Q]: Question: A grocer purchased 20 kg of rice at the rate of 15 per kg and 30 kg of rice at the rate of 13 per kg. At what price per kg should he sell the mixture to earn 331/3% profit on the cost price?

Option A: 28.0

Option B: 20.0

Option C: 18.4

Option D: 17.4

Option E: None of these
[EX A]:
Option C