A number is chosen at random from 1 to 10. Find the probability of not selecting a multiple of 3.

First, you need to figure out how many of the numbers are multiples of 3. The numbers 3, 6, and 9 are all multiples of three, so three numbers are thrown out of the probability.

There are now 7 numbers left. Your probability is out of ten, so there is a 7/10 of a chance to not pull a number that is a multiple of 3.

The probability is 9/10 or 90%