Alice rolls a fair six sided die, and Bob rolls a fair twenty sided die. What is the probability that the product of the numbers they roll is a multiple of 5?
There are \(6 \times 20 = 120 \) total outcomes.
Of these, \(5 \times 16 = 80\) outcomes have neither Alice nor Bob rolling a multiple of 5
So, there are \(120 - 80 = 40\) successes, so the probability is \({40 \over 120} = \color{brown}\boxed{1 \over 3}\)