math
posted by Zoe y on .
Question: It was discovered that 1 outa every 5 selected adults visits disney world every year. If 30 adults are randomly selected what is the probability that exactly 7 of them will visit disney this year?
answer: .154 BUT I CANNOT FIGURE HOW THEY CAME UP WITH THIS ANSWER.. PLEASE HELP!

C(30,7)(1/5)^7(4/5)^23 = .15382