In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[EX Q]: Problem: village x has a population of 76000 , which is decreasing at the rate of 1200 per year . village y has a population of 42000 , which is increasing at the rate of 800 per year . in how many years will the population of the two villages be equal ? 
Options: a ) 15 , b ) 17 , c ) 11 , d ) 18 , e ) 13
[EX A]: b

[EX Q]: Problem: x varies inversely as square of y . given that y = 3 for x = 1 . the value of x for y = 6 will be equal to : 
Options: a ) 3 , b ) 6 , c ) 1 / 4 , d ) 1 / 3 , e ) 9
[EX A]: c

[EX Q]: Problem: if 3 ^ x * 4 ^ y = 19683 and x – y = 9 , then x = ? 
Options: a ) 8 , b ) 9 , c ) 10 , d ) 11 , e ) 12
[EX A]:
b