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: Two alloys A and B are composed of two basic elements. The ratios of the compositions of the two basic elements in the two alloys are 5 : 3 and 1 : 2, respectively. A new alloy X is formed by mixing the two alloys A and B in the ratio 4 : 3. What is the ratio of the composition of the two basic elements in alloy X ?

 Option A: 1 : 1

 Option B: 2 : 3

 Option C: 5 : 2

 Option D: 4 : 3

 Option E: 7 : 9
[EX A]: Option A

[EX Q]: Question: If 3^x*4^y = 1,594,323 and x – y = 13, then x = ?

 Option A: 10

 Option B: 11

 Option C: 12

 Option D: 13

 Option E: 14
[EX A]: Option D

[EX Q]: Question: A train 250 m long running at 72 kmph crosses a platform in 30 sec. What is the length of the platform?

 Option A: 350m

 Option B: 200m

 Option C: 250m

 Option D: 270m

 Option E: 300 m
[EX A]:
Option A