GMATD11 wrote:

133. Are all of the numbers in a certain list of 15 numbers

equal?

(1) The sum of all the numbers in the list is 60.

(2) The sum of any 3 numbers in the list is 12.

how option 2 is sufficient

statement 1 is clearly insufficient as the some numbers could repeat and give more than one solution

Statement 2 is sufficient as it states that sum of any 3 numbers is 12.

i.e. is a1,a2,a3....a15 are the numbers then

a1+a5+a6 = a1+a3+a15= ....= 12

this is only sufficient when all the numbers are equal.

Hence B