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.

Q: 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

A: Option A
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Q: Question: A, B and C invested Rs.6300, Rs.4200 and Rs.10500 respectively, in a partnership business. Find the share of A in profit of Rs.12700 after a year?

 Option A: 3630

 Option B: 9232

 Option C: 8828

 Option D: 2387

 Option E: 3810

A: Option E
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Q: Question: A survey reveals that the average income of a company’s customers is $50,000 per year. If 50 customers respond to the survey and the average income of the wealthiest 10 of those customers is $75,000, what is the average income of the other 40 customers?
Is there a way to solve this using weighted average concept instead of doing tedious calculations?

 Option A:  $27,500

 Option B:  $43,750

 Option C:  $37,500

 Option D:  $42,500

 Option E:  $50,000

A:
Option B
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