Use the binomial distribution to find the expected number of purple-eyed flies (from a mutant parent) after n have been checked. How many must be checked for the expectation to equal 1?
A lab is screening to find mutant flies. 10% of the offspring of mutant flies have purple eyes, while none of the offspring of wild type flies have purple eyes. Suppose that purple-eyed flies are just as easy to catch as ordinary flies.