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: A cycle is bought for Rs.900 and sold for Rs.1150, find the gain percent?

 Option A: 15

 Option B: 20

 Option C: 27.77

 Option D: 40

 Option E: 12
[EX A]: Option C

[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: It costs Rs. x each to make the first thousand copies of a compact disk and Rs. y to make each subsequent copy. If z is greater than 1,000, how many Rupees will it cost to make z copies of the compact disk?

 Option A: 1000 x + yz

 Option B: zx - zy

 Option C: 1000 (z - x

 Option D: 1000 (z - y

 Option E: 1000 (x- y
[EX A]:
Option E