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: How much time does a train 150 metres long running at 90 km/hr take to pass a pole?

 Option A: 7.9s

 Option B: 6s

 Option C: 7.5s

 Option D: 7.6s

 Option E: 7.4s

A: Option B
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Q: Question: Find the sum lend at C.I. at 5 p.c per annum will amount to Rs.441 in 2 years?

 Option A: Rs.900

 Option B: Rs.800

 Option C: Rs.500

 Option D: Rs. 400

 Option E: Rs.200

A: Option D
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Q: Question: If a and b are different values and a – b = 4(√a - √b), then in terms of b, a equals:

 Option A: √b

 Option B: b

 Option C: b - 8√b + 16

 Option D: b + 2√b + 1

 Option E: b^2 – 2b√b + b

A:
Option C
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