A multiple choice examination has 5 questions. Each question has three alternative answers of which exactly one is correct. The probability that a student will get at least one correct answer is

Step-by-step solution

There are 5 questions and each question has 3 options of which one is correct. Probability of getting correct answer = 1 3 Thus n =5, p = 1 3 , q = 2 3 P (at least one correct answer) =1-P( None is correct )=1- 5 0 ( 1 3 )⁰ ( 2 3 )⁵=1-1 1 32 243 = 243-32 243 = 211 243