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: 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
[EX A]: Option B

[EX Q]: Question: In what time will a train 200 m long cross an electric pole, it its speed be 144 km/hr?

Option A: 2.5 sec

Option B: 2.9 sec

Option C: 3.5 sec

Option D: 7.5 sec

Option E: 5 sec
[EX A]: Option E

[EX Q]: Question: A bat is bought for Rs.440 and sold at a gain of 20% find its selling price

Option A: s.430/-

Option B: s.480/-

Option C: s.400/-

Option D: s.528/-

Option E: s.600/-
[EX A]:
Option D