Each house number on a street has 2 nonzero digits that are different. What is the probability that the second digit is less than 3, given that the first digit is less than 3?
You again! Since we have only 2 numbers less than 3 (that is 1 and 2) the first house number digit gets 2 out of 9 chance. But the second one can't be repeated so it gets only one number out of the remaining 8. The answer is 1/8.
