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

[EX Q]: Problem: the average of first six prime numbers greater than 20 is ?
[EX A]: 3

[EX Q]: Problem: a store reduced the price of all items in the store by 12 % on the first day and by another 10 % on the second day . the price of items on the second day was what percent of the price before the first reduction took place ?
[EX A]: 79.2

[EX Q]: Problem: every disk in a bag is either blue , yellow or green . the ratio of blue disks to yellow disks to green disks in this bag is 3 : 7 : 8 . if the total number of disks in the bag is 144 , how many more green disks than blue disks are in the bag ?
[EX A]:
4