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

Example Input: Problem: the probability is 1 / 2 that a certain coin turns up heads on any given toss . if the coin is tossed 6 times , what is the probability that the coin turns up tails on at least one of the tosses ?
Example Output: 63 / 64

Example Input: Problem: find ( 7 x + 2 y ) / ( x - 2 y ) if x / 2 y = 3 / 2 ?
Example Output: 23

Example Input: Problem: in one hour , a boat goes 7 km along the steram and 5 km against the stream . the speed of the boat in still waer ( in km / hr ) is :
Example Output:
6