It’s easier to see with actual numbers therefore, since you are not given a total, say there are 20 Which means, 10 are peanuts, 5 are chocolate candies and 5 are dried fruit. Out of the 20 options, there are 5 that are the chocolate candies. This means there is a 5 in 20 chance you will pick the chocolate candies. 5/20 = ¼ (i.e. the likelihood to pick one is the same as the fraction of chocolate candies the bag contains)