Question 1048562
At least one means 1- p(0) are rotten
1-(0.8)^5=0.67232
Given that at least one egg is rotten, then there are 4 possibilities.  The probability that no more are rotten is 1-0.8^4=0.5904.
In this instance, we assume independence of trials.  Once one egg is rotten, the chances don't change for another, but the opportunity for it decreases from 5 to 4 trials.