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: (3x + 1) (2x - 5) = ax^2 + kx + n . What is the value of a - n + k ?

 Option A: 5

 Option B: 8

 Option C: 9

 Option D: 14

 Option E: 11
answer:
Option D


question:
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
answer:
Option D


question:
Question: If (1/2)^22 (1/81)^k = 1/18^22, then k =

 Option A: 8

 Option B: 12

 Option C: 16

 Option D: 24

 Option E: 11
answer:

Option E