Question

You randomly select an integer from 0 to 9 (inclusively) and then randomly select and integer from 0 to 7 what is the probability of selecting a 2 both times

Answer 1

Answer: 1/80

Reason:

Set A = {0,1,2,3,4,5,6,7,8,9}

Set B = {0,1,2,3,4,5,6,7}

The probability of getting a "2" from set A is 1/10 since there is one copy of "2" that we want out of ten values total.

The probability of getting a "2" from set B is 1/8 for similar reasoning. This time there are eight numbers in this set.

Multiply those fractions mentioned (1/10)*(1/8) = 1/80

This fraction converts to the exact decimal value of 0.0125, meaning there's exactly a 1.25% chance of getting "2" twice in a row.