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: In the xy-plane, a line has slope 5 and x-intercept 3. What is the y-intercept of the line?

 Option A: -15

 Option B: -3

 Option C: 0

 Option D: 3

 Option E: 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 waiter's salary consists of his salary and tips. During one week his tips were 5/4 of his salary. What fraction of his income came from tips ?

 Option A: 4/9

 Option B: 5/4

 Option C: 5/8

 Option D: 5/9

 Option E: 6/9
[EX A]:
Option D