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: Find the average of all the numbers between 11 and 36 which are divisible by 5

Option A: 15

Option B: 20

Option C: 25

Option D: 30

Option E: 35
answer:
Option C

question:
Question: A can complete the job in 4 hours and B can complete the same job in 3 hours. A works for 1 hour and then B joins and both complete the job. What fraction of the job did B complete

Option A: 1/7

Option B: 3/10

Option C: 1/2

Option D: 5/6

Option E: 8/9
answer:
Option A

question:
Question: Smith can do a work in 15 days while Johnson can do it in 25 days. How long will they take if both work together?

Option A: 3 4/9 days

Option B: 8 4/9 days

Option C: 9 3/8 days

Option D: 6 3/8 days

Option E: 7 3/8 days
answer:
Option C