Solving probability is finding the likely hood of an event. So for example if you have 4 red circles and 3 yellow and you were trying to find the probability of picking yellow, you would add all of the blocks together. After you would put the problem into a fraction; with 3(the amount we are given) on top and 7(the total) on the bottom. I hope that helps but if it’s a more specific question, let me know!