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: A certain sum earns simple interest of Rs. 800 in 2 years at a certain rate of interest. If the same sum earns compound interest of Rs.900in the same period of 2 years, What must be the rate of interest?

 Option A: 25%

 Option B: 10%

 Option C: 15%

 Option D: 20%

 Option E: 30%

Answer: Option A


Question: Question: A group of boy scouts and girls scouts is going on a rafting trip. 45% of the scouts arrived with signed permission slips. If 60% of the scouts were boy scouts and 25% of the boy scouts arrived with signed permission slips, then what percentage of the scouts were girl scouts who arrived with signed permission slips?

 Option A: 20

 Option B: 21

 Option C: 25

 Option D: 28

 Option E: 30

Answer: Option E


Question: Question: On an order of 5 dozen boxes of a consumer product, a retailer receives an extra dozen free. This is equivalent to allowing him a discount of:

 Option A: 15%

 Option B: 16 1/6%

 Option C: 16 2/3%

 Option D: 20%

 Option E: 30%

Answer:
Option C