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

Example Input: Problem: what ratio must a shopkeeper mix peas and soybean of rs . 16 and rs . 25 / kg , as to obtain a mixture of rs . 21.50 ?
Example Output: 7 : 11

Example Input: Problem: two numbers are in the ratio 3 : 5 . if 9 be subtracted from each , they are in the ratio of 1 : 2 . the first number is :
Example Output: a ) 27

Example Input: Problem: a , b , c can complete a piece of work in 3,9 and 15 days respectively . working together , they will complete the same work in how many days ?
Example Output:
45 / 23