Since Hank is allergic to chocolate, he cannot eat Reese's, Snickers, Hershey's bars, or any other type of chocolate candy.
Therefore, the only candy that Hank can eat is the Sour Patch Kids and Skittles.
The total number of Sour Patch Kids that Hank has is 5.
The total number of Skittles that Hank has is 6 packs, or 6 * the number of Skittles in one pack (let's assume it's 10 Skittles per pack). So, the total number of Skittles that Hank has is 6 * 10 = 60.
Adding the number of Sour Patch Kids and Skittles, the total number of candy that Hank can eat is 5 + 60 = 65.
The total amount of candy that Hank has is 8 Reece's + 12 Snickers + 5 Sour Patch Kids + 4 Hershey's bars + 6 packs of Skittles = 8 + 12 + 5 + 4 + 6 * 10 = 8 + 12 + 5 + 4 + 60 = 89.
The ratio of candy that Hank can eat to the total amount of candy he has is 65 / 89 = approximately 0.73, which can be expressed as a simplified fraction as 73 / 100.