Hi Binomial Distribution: p(does not spoil) = .95 and q(spoil) = .05 n = 15 Using Ti or similarly an inexpensive calculator like a Casio fx-115 ES plus P(x = 0) = basically 0 P(x ≤ 12) = .0307 P( x ≥ 9) = 1 - P(x ≤ 8) 1 - .000003 = .999997 Wish You the Best in your Studies.