Pretty sure it would be 30 I hope this helps
For example, if you're trying to calculate the probability of pulling a blue marble out of a bag of 20 marbles, and 4 of those 20 marbles are blue, you'd divide 4 (the number of blue marbles, aka your desired outcome) by 20 (the total number of outcomes). This gets you a probability of 0.2, or 20%.