DS 3 ( originally posted by tutonaranjo)

gabriel wrote:2) A certain list consists of several different integers. Is the product of all the integers on the list positive?
1) The product of the greatest and the smallest integers on the list is positive
2) There is an even number of integers in the list.

Answer is C (don't understand why not E)

If the product of the largest and smallest integer is positive that means that all the numbers have the same sign which is either positive or negative ..

.. now if all of them are positive then the product of all of them would also be positive ..

if all of them are negative then it would depend if the number of integers are even or odd .. if the number of integers is odd then the product of all of them will be negative and if it is even then the product will be positive ... sine the first statement doesnt tell us whether the number of integers are even or odd .. so it is insufficient ..

the second statement is obviously by it self insufficient ...

Combine the 2 statements and u know that the product will always be positive ..

got this one
my begginer mind somehow thought that the largest integer and smallest integer were -4 and -1 in a -1,0,1,2,3-4 set
I know, I know
thanks for your patience.