SOLUTION: a student takes a 10 question mutiple choice quiz with 5 choices for each question, find the probility of guessing at least 7 correct out of 10

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: a student takes a 10 question mutiple choice quiz with 5 choices for each question, find the probility of guessing at least 7 correct out of 10      Log On


   

Question 168946: a student takes a 10 question mutiple choice quiz with 5 choices for each question, find the probility of guessing at least 7 correct out of 10
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The student has a 1/5 chance of getting any certain question right
The sudent wants to repeat this lucky guess 7 times
This is like rolling a 5-sided dice 7 times and getting the same
number each time
The probability is
1%2F5+%2A+1%2F5+%2A+1%2F5+%2A+1%2F5+%2A+1%2F5+%2A+1%2F5+%2A+1%2F5+=+1%2F15625
That's my guess, but I'm often wrong on probability
questions, so get another opinion