SOLUTION: If a student can solve one of 4 problems. If he attempts 4 questions in succession. What is the probability that at least one of them is right?

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Question 884041: If a student can solve one of 4 problems. If he attempts 4 questions in succession. What is the probability that at least one of them is right?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
First find the probability that all of them are wrong.
P=%283%2F4%29%283%2F4%29%283%2F4%29%283%2F4%29=81%2F256
The probability of at least one right plus the probability of all wrong must sum to 1.
81%2F256%2BP%281R%29=1
P%281R%29=256%2F256-81%2F256
P%281R%29=175%2F256