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: A fish can go upstream at 35 kmph and downstream at 55 kmph, and then find the speed of the fish in still water?

 Option A: 45

 Option B: 55

 Option C: 35

 Option D: 65

 Option E: 70

A: Option A
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Q: Question: If the average (arithmetic mean) of x, x + 2, and x + 4 is 33, what is the value of x?

 Option A: 30

 Option B: 31

 Option C: 32

 Option D: 32

 Option E: 37

A: Option B
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Q: Question: A sum of Rs. 2900 amounts to Rs. 3422 in 3 years. Had the rate of interest be 5% higher then what would the sum amount in the same time period?

 Option A: Rs. 4465

 Option B: Rs. 3683

 Option C: Rs. 3596

 Option D: Rs. 3857

 Option E: None of these

A:
Option D
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