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.

[EX Q]: Question: The avg weight of A,B & C is 80 kg. If D joins the group, the avg weight of the group becomes 82 kg.If another man E who weights is 3 kg more than D Replaces A, Then the avgof B,C,D&E becomes 81 kg. What is the weight of A?

 Option A: 56

 Option B: 65

 Option C: 75

 Option D: 89

 Option E: 95
[EX A]: Option E

[EX Q]: Question: A train 125m long takes 6 sec to cross a man walking at 5kmph in a direction opposite to that of the train. Find the speed of the train?

 Option A: 65kmph

 Option B: 70kmph

 Option C: 75kmph

 Option D: 80kmph

 Option E: 85kmph
[EX A]: Option B

[EX Q]: Question: The value of 1/(1-x) + 1/ (1+x) + 2/(1+x^2) + 4/(1+x^4)

 Option A: 8/(1-x^8

 Option B: 4x/(1+x^2

 Option C: 4/(1-x^6

 Option D: 4/(1+x^4

 Option E: 4x/(1-x^4
[EX A]:
Option A