Willard has just been given a 10 question multiple choice test in one of his classes. Each question has five answers only one of which is correct. Since Willard has not attended class recently, he does not know any of the answers. Assume that Willard guesses randomly on all ten questions. Find the probability that he will answer, at most, three questions correctly.

a .80

b .88

c .70

d .50

e .77

ive tried to use the formula but still am not getting the correct answer please help!

p ( x ) = n ! x ! (n-x ) ! . px qn-x "( P + q = 1 9 = 2 - p For Questions 9 and 10 use the Binomial Probability Table . 8 x . B x 8 x 8 . 8 7 8 8 8 n = 10 9. Willard has just been given a ten-question multiple-choice test in one of his classes. 1= 1/5 =.20 Each question has five answers only one of which is correct. Since Willard has not POLIM attended class recently, he does not know any of the answers. Assume that Willard (190109 9 = 1-. 20 80 guesses randomly on all ten questions. Find the probability that he will answer, at most, X = 3 3 questions correctly. A) 0.80 B) 0.88 3424800 = 120 x. 20* *. 8075 5 910401018 C) 0.70 4 (5040 ) D) 0.50 30240 120 x. 008 * 20 9 715 2 E) 0.77 10 014 717 210 . 0 0 1 4 7 7 722 10 510. Assume that 65% of the cars on a freeway are traveling faster than 75 miles per hour. A random sample of 12 cars was observed under normal driving conditions with no police miles per hour? car in sight. What is the probability that more than 6 of them were going faster than 75 A) 98% B) 88% C) 79% D) 65% E) 92% BO LACE