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.
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Question: Question: For positive integers x and z, which of the following can be written as z^2?

 Option A: x^2+1

 Option B: x^2-1

 Option C: x^2-24

 Option D: x^2+11

 Option E: x^2-11

Answer: Option D


Question: Question: For any positive integer Y, the sum of the first Y positive integers equals Y(Y+1)/2 . If X and Y are positive integers and X > Y, what is the sum of all the integers between X and Y, inclusive?

 Option A:  X(X+1

 Option B:  X(X+1

 Option C:  X(X+1

 Option D:  X(X+1

 Option E:  X(Y+1

Answer: Option B


Question: Question: Ayesha's father was 58 years of age when she was born while her mother was 42 years old when her brother four years younger to her was born. What is the difference between the ages of her parents?

 Option A: 6

 Option B: 40

 Option C: 50

 Option D: 10

 Option E: 20

Answer:
Option E