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: Raman buys an old scooter for Rs. 5000 and spends Rs. 1000 on its repairs. If he sells the scooter for Rs. 7200, his gain percent is :

 Option A: 20%

 Option B: 12%

 Option C: 10%

 Option D: 5%

 Option E: None of these

Answer: Option A


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: A pair of articles was bought for $900 at a discount of 10%. What must be the marked price of each of the article?

 Option A: $300

 Option B: $500

 Option C: $350

 Option D: $400

 Option E: $600

Answer:
Option B