Answer:
(19/23)(18/22)(17/21) or 969/1771
Explanation:
You add up the total number of cans, giving you 6+4+5+8 = 23 cans total. From there, you only have 4 cans of grape juice. That means 19 of these cans aren't grape, meaning you are checking the probability of choosing these three times in a row.
The probability of selecting the first can and it not being grape is 19/23. Then, when you select another can in succession, without replacing the cans, you now only have 22 cans left, meaning 18 also will not be grape, so it will be a 18/22 chance. Then, selecting your third can, 21 cans are left, and 17 of them are not grape since you have not yet chosen one, giving you 17/21. You multiply them together.
Hopefully I reduced the fraction properly (or even did this question properly)