Abag contains 5red balls and 8 blue balls, it also contains 4 green and 7 black balls is drawn at random. then find the probability that it is not green

80% of the balls are not green. First, you must add the total amount of balls. 5+8+4+7 = 20. Since the problem says that they are 4 green balls, you must subtract 20-4. This is because you are trying to find the probability of balls that are not green. 20-4 = 16, so convert this to 16/20. To make 16/20 into a percentage, (because you’re finding the probability) you must multiply the fraction by 5/5. Once you do that, you will get 80/100. Therefore, 80% of the total amount of balls are not green.