instruction:
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:
Question: A box contains 9 pairs of shoes (18 shoes in total). If two shoes are selected at random, what it is the probability that they are matching shoes?

 Option A: 1/190

 Option B: 1/17

 Option C: 1/19

 Option D: 1/10

 Option E: 1/9
answer:
Option B


question:
Question: The average age of 15 students of a class is 15 years. Out of these, the average age of 4 students is 14 years and that of the other 10 students is 16 years, The age of the 15th student is

 Option A: 11

 Option B: 12

 Option C: 9

 Option D: 14

 Option E: 15
answer:
Option C


question:
Question: Worker A takes 8 hours to do a job. Worker B takes 12 hours to do the same job. How long it take both A & B, working together but independently, to do the same job?

 Option A: 40 days

 Option B: 24/5 days

 Option C: 39/9 days

 Option D: 30/9 days

 Option E: 60/9 days
answer:

Option B