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.
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Question: Question: The number of diagonals of a polygon of n sides is given by the formula z=n(n-3)/2. If a polygon has twice as many diagonals as sides, how many sides does it have?

 Option A:  3

 Option B:  5

 Option C:  6

 Option D:  7

 Option E:  8

Answer: Option B


Question: Question: If 3^x*4^y = 1,594,323 and x – y = 13, then x = ?

 Option A: 10

 Option B: 11

 Option C: 12

 Option D: 13

 Option E: 14

Answer: Option D


Question: Question: An auction house charges a commission of 15% on the first $50,000 of the sale price of an item, plus 10% on the amount of of the sale price in excess of $50,000. What was the price of a painting for which the house charged a total commission of $24,000?

 Option A: $115,000

 Option B: $160,000

 Option C: $215,000

 Option D: $240,000

 Option E: $365,000

Answer:
Option C