There would be a 44.4% chance of either of these happening.
In order to find this we have to find out how many total possibilities there are. Because we have two die each with 6 sides, we have 36 total options.
Of those options, 12 of them start with either a 3 or 6, which are multiples of 3. So we can add 12 to our lists of successes.
Of those options, there are 4 more that don't start with those numbers, but do equal 7. (1 and 6, 2 and 5, 4 and 3, 5 and 2). So we can add 4 to our list of successes.
Knowing we have 12 and 4 successes, we can add them together to get 16. We can then divide that by the total options (36) to find the percentage above.
