Question

3. A multiple choice test contains 15 questions. Each question has four options, only one of

which is correct. What is the probability of guessing exactly 9 questions correctly?

Answer 1

`(5005* 3^6)/(4^(15))`

Explanation:

by using binomial property, we get the probability

`P=C^(15)_(9)* (1)/(4^9)* (3^6)/(4^6)`