To find the probability of a number that is multiple of 9 from 1 through 20 multiply nine by numbers starting at one and keep working till you pass 20 so 1*9 is 9, and 2*9 is 18 but 3*9 is 27 which is passed 20 so only two numbers are a multiple of 9, 9 and 18. That means the probability of pulling out a multiple of 9 is 2/20 or 1/10 or a 10% chance
