I assume you mean EXACTLY 4 of 5.
This is a binomial rv with n=5 and p=1/3... .
So, E is correct.
The probability that a student passes an exam is 1/3. If 5 people took the exam, what is the probability that only 4 of them pass?
A. (1/3)^5
B. 4(2/3)^4 * 4(1/3)
C. 4(1/3)^4 * (2/3)
D. (2/3)^5
E. 5(1/3)^4 * (2/3)
F. None of the above
Can someone post up what the answer is and an explanation for this?