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 LCM of two numbers is 2310 and HCF is 26. If one of the numbers is 210. Then what is the other number ?

 Option A: 715

 Option B: 825

 Option C: 286

 Option D: 582

 Option E: 465
[EX A]: Option C

[EX Q]: Question: If x < y < 0, which of the following must be true?

 Option A: 2xy/3x is a negative integer

 Option B: x-y is a positive integer

 Option C: (-x

 Option D: x/y is a negative integer

 Option E: 2x+y is a negative integer
[EX A]: Option C

[EX Q]: Question: The mean of 15 observations was 25. It was found later that an observation 40 was wrongly taken as 25. The corrected new mean is

 Option A: 20

 Option B: 30

 Option C: 15

 Option D: 18

 Option E: 26
[EX A]:
Option E