The task is to generate the correct answer for a given math problem.

[EX Q]: Problem: the ratio between b and y is 7 / 9 ; b and y are increased by 4 , what is the ratio between the new values of b and y ?
[EX A]: it can not be determine

[EX Q]: Problem: tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random . what is the probability taht the ticket drawn has a number which is a multiple of 3 or 5 ?
[EX A]: 9 / 20

[EX Q]: Problem: the market value of a certain machine decreased by 10 percent of its purchase price each year . if the machine was purchased in 1982 for its market value of $ 8000 , what was its market value two years later ?
[EX A]:
$ 6,400