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: 3 + 3 + 3 + 2 × 3^2 + 2 × 3^3 + 2 × 3^4 + 2 × 3^5 + 2 × 3^6 + 2 × 3^7 =

 Option A: 3^7

 Option B: 3^8

 Option C: 3^14

 Option D: 3^28

 Option E: 3^30

Answer: Option B


Question: Question: Rahim bought 4 pillows with the average cost of $5. If Rahim also buys the fifth pillow with the price of $ 10, what is the average (arithmetic mean) price of those 5 pillows?

 Option A: $6

 Option B: $5

 Option C: $5.5

 Option D: $6.5

 Option E: $7

Answer: Option A


Question: Question: Company S produces two kinds of stereos: basic and deluxe. Of the stereos produced by Company S last month, 2/3 were basic and the rest were deluxe. If it takes 1.6 as many hours to produce a deluxe stereo as it does to produce a basic stereo, then the number of hours it took to produce the deluxe stereos last month was what fraction of the total number of hours it took to produce all the stereos?

 Option A: 7/17

 Option B: 14/31

 Option C: 7/15

 Option D: 17/35

 Option E: 1/2

Answer:
Option E