SLUG Aptitude Practice Test

Probability is found by counting how many favorable outcomes there are over the total number of possible outcomes. Here, there are 60 red balls out of 100 total balls, so the chance of drawing red is 60/100, which simplifies to 3/5 (60%). That matches the actual counts: you’d expect red about 60% of the time. For reference, 4/5 would require 80 red balls, 1/2 would mean equal red and blue, and 5/6 would mean about 83 red balls, none of which reflect the given numbers.