The task is to generate the correct answer for a given math problem.
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Question: Problem: the average of first six prime numbers greater than 20 is ?

Answer: 3


Question: Problem: if the sides of a cube are in the ratio 5 : 3 . what is the ratio of their diagonals ?

Answer: 5 : 3'


Question: Problem: for all numbers a and b , the operation is defined by ab = ( a + 2 ) ( b – 3 ) . if 3 x = – 20 , then x =

Answer:
-