05:0705:07, 30 March 2020diffhist−1
Eye of Ender
Changed average number of throws back to five. The average of a probability distribution is the sum of the probability of each possibility multiplied by the value of that possibility. So you need to take the sum from 1 -> ∞ of (1-0.2)^(n-1)*0.2. This is exactly equal to 5.