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: an article with cost price of 180 is sold at 15% profit. what is the selling price?

Option A: 198

Option B: 200

Option C: 204

Option D: 207

Option E: 210
Option D

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
Option C

Question: The average of five numbers id 29. If one number is excluded, the average becomes 25. What is the excluded number?

Option A: 30

Option B: 40

Option C: 32.5

Option D: 45

Option E: 37
Option D