The total number of combinations of 3 from 6 = 6C3 = 20 All possible combinations of 3 which have a product divisible by 3 must contain either a 3 or a 6. So the number not divisible must be 3 combinations from the number 1, 2, 4 and 5.= which is 4
So the required probability is 20-4 ? 20 = 16/20 = 0.8 Answer
