Question

A number is randomly chosen from the set of (-3,-2,-1,0,1) and another number is randomly chosen from the set (-1,2,5). What is the probablity that the product of the two chosen numbers is negative

Answer 1

7/15

Explanation:

To have a negative number as a result of a product between two numbers, we need one number to be negative and one to be positive. So our options are: -3 and 2, -3 and 5, -2 and 2, -2 and 5, -1 and 2, -1 and 5, 1 and -1

As we have 5 numbers in the first group and 3 in the second, we have 5*3=15 possibilities, and inside these 15, we want 7 of them (the 7 possibilities that gives us a negative product listed above), so the probability we want is 7/15 (the possibilities we want over all the possibilities)