Answer: 0%
Explanation:
There are 5 colors of jelly beans.
Kaz ate all the green beans, so now only 80% of the jelly beans remain.
Kaz ate half of the orange pieces so now only 70% of the jelly beans remain.
Then Kaz ate half of the remaining pieces, so only 35% of the beans remain.
Current numbers: 0% green, 5% orange, 10% red, yellow, blue
Then he eats red and yellow candies in equal proportions until only 15% of the beans remain. This means that he ate 20% worth of red and yellow beans. This means that he ate all of the red and yellow beans.
Thus, there are 0% red beans left.