This is a binomial distribution where 80% of flights arrive on time (p = 0.8) and 20% do not (q = 1 - 0.8 = 0.2). Then the probability that exactly 2 flights arrive late follows the formula:
(nCr)(p^r)(q^(n-r)), where n = 16 (total # of flights), r = 14 (flights that arrive on time)
(16C14)(0.8^14)(0.2^2) = 0.2111