So 20% is 1/5 and 1/5 of 55 is 11. That means there are in total 11 blue candies if 1/5 of them is damaged then technically 2.2 of them are which is kinda weird as it doesn't give whole number
Percentage is based off of 1 or 100% which is equal to 1. So 50% or half of both 100% and 1 would be translated as .5 and as the percentage becomes more accurate or lengthy you add to the decimal so 53% is .53 and 53.4% is .534