It is the same as saying that a 0 is picked, either as 1st or 2nd pick:
(1/6)(1) + (5/6)(1/5) = 1/3
In a set of 6 numbers, {-2, -1, 0, 1, 2, 3}, what is the probability the product of any two numbers is zero?
2 answers
maybe:
same as the probability that one of the numbers you choose is zero probability that first one is zero = 1/6
probability that second one is zero also is 1/6
so sum is 2/6 = 1/3
same as the probability that one of the numbers you choose is zero probability that first one is zero = 1/6
probability that second one is zero also is 1/6
so sum is 2/6 = 1/3