SOLUTION: Each question of a 5-question multiple choice exam has 4 possible answers. Suppose a student picks an answer at random for each question. Find the probability the student selects t

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Question 564862: Each question of a 5-question multiple choice exam has 4 possible answers. Suppose a student picks an answer at random for each question. Find the probability the student selects the correct answer on only the first question.
What is the formula I will use to solve this problem?
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
No formula, just a little logic.

The student has to answer the first question correctly (this has probability 1/4) and answer the other four incorrectly (each has probably 3/4). Therefore the probability we want is

(1/4)(3/4)(3/4)(3/4)(3/4)

= 81/1024