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

[Q]: Problem: a man is 28 years older than his son . in two years , his age will be twice the age of his son . the present age of the son is ?
[A]: 26


[Q]: Problem: a man whose speed is 4.5 kmph in still water rows to a certain upstream point and back to the starting point in a river which flows at 1.5 kmph , find his average speed for the total journey ?
[A]: 4


[Q]: Problem: if the price of a certain computer increased 30 percent from x dollars to 351 dollars , then 2 x =
[A]:
540