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


[Q]: Question: How many positive integers G less than 10,000 are such that the product of their digits is 210?

 Option A: 24

 Option B: 30

 Option C: 48

 Option D: 54

 Option E: 72
[A]: Option D


[Q]: Question: From the given equation find the value of y: yÂ² + y - 20

 Option A: 5

 Option B: 4

 Option C: 3

 Option D: 2

 Option E: 1
[A]:
Option B