Data Sufficiency

If the average (arithmetic mean) of six different numbers is 25, how many of the numbers are greater than 25?

1) None of the six numbers is greater than 50.
2) Three of the six numbers are 7, 8, and 9, respectively.

OA: C

rahul.s wrote:If the average (arithmetic mean) of six different numbers is 25, how many of the numbers are greater than 25?

1) None of the six numbers is greater than 50.
2) Three of the six numbers are 7, 8, and 9, respectively.

OA: C

Sum of all 6 numbers = 150

1.) says none of the numbers are greater than 50 - Insuff

2) if three of the numbers are 7,8 and 9 the sum of other 3 is = 126 (again not sufficient , it could be 124,1,1 or 40,40,46)

combining one and 2 if none of the numbers are greater than 50, and the sum is 126 each of the numbers should be greater than 25 (worst case: two numbers 50,50 third num should be 26 which is greater than 25)

Hence 1&2 combined is sufficient