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

Example Input: Problem: x varies inversely as square of y . given that y = 3 for x = 1 . the value of x for y = 9 will be equal to :
Example Output: 1 / 9

Example Input: Problem: the cost of the paint is rs . 50 per kg . if 1 kg of paint covers 20 sq . ft , how much will it cost to paint outside of a cube having 20 feet each side
Example Output: rs . 6000

Example Input: Problem: laxmi and prasanna set on a journey . laxmi moves northwards at a speed of 20 kmph and prasanna moves southward at a speed of 30 kmph . how far will be prasanna from laxmi after 60 minutes ?
Example Output:
50