If a student randomly guesses at 20 multiple-choice questions, find the probability that the student gets exactly four correct. Each question has four possible choices. 0.190 0.162 0.085 0.218

The probability of getting first 4 right and the rest wrong = (1/4) ^4 * (3/4) ^16

there are 20C5 ways = 4845 ways of getting 4 right out of 20 so required propability is (1/4) ^4 * (3/4) ^16 * 4845 = 0.190 answer