Question

Alex receives 55 emails a day. Out of the 55 emails, 12 emails are spam. If Alex opens 6 emails at random, what is the probability that none of the emails are spam? Enter your answer in decimal form rounded to the nearest thousandths.

Answer 1

He receives 55 emails. Out of the 55 emails, 12 emails are spam. He opens 6 emails at random. The probability that none of the mails are spam can be calculated as follows

emails that are not spams = 55 - 12 = 43 emails

`(43)/(55)*(42)/(54)*(41)/(53)*(40)/(52)*(39)/(51)*(38)/(50)=(4389446880)/(20872566000)=0.21029742485\approx0.210`