SOLUTION: How do you solve: An unprepared student makes random guesses for the ten true-false questions on a quiz. Find the probability that there is at least one correct answer. Thank

Algebra ->  Probability-and-statistics -> SOLUTION: How do you solve: An unprepared student makes random guesses for the ten true-false questions on a quiz. Find the probability that there is at least one correct answer. Thank      Log On


   

Question 372516: How do you solve:
An unprepared student makes random guesses for the ten true-false questions on a quiz. Find the probability that there is at least one correct answer.
Thank you very much!
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
We'll work the problem backwards.
Let find the probability that every answer is incorrect.
P%28T%29=0.5
P%28F%29=0.5
P%2810F%29=0.5%5E10
.
.
P(at least 1 T)+P(10F)=1
P(at least 1 T)=1-P%2810F%29
P(at least 1 T)=1-0.5%5E10
P(at least 1 T)=0.9990234