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

Example Input: Problem: a person want to give his money of $ 1800 to his 3 children a , b , c in the ratio 2 : 3 : 4 . what is the b ' s share ?
Example Output: $ 600

Example Input: Problem: in the first 20 overs of a cricket game , the run rate was only 4.8 . what should be the run rate in the remaining 30 overs to reach the target of 302 runs ?
Example Output: 6.87

Example Input: Problem: a set of pictures of butterflies contains 10 pictures . jim bought 3 of the pictures . if 2 pictures are to be picked out from the 10 pictures , what is the probability that both pictures are not those that were already bought by jim ?
Example Output:
7 / 15