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## A dump of our free Chat sessions, in case it is useful. It excludes white boards used during paid sessions.

student : A class is given a surprise 10 question multiple choice quiz over material they were supposed to study. Since none of the students are prepared, they are forced to guess the answers. The probability that a guess on any question is right is 20%.

Find the probability that a student is able to guess at least 6 correct answers.
tutor3 : probability of more than 6 correct answers by guessing is .2*.2*.2*.2*.2* =.000032 as probabilty of a correct answer on guess is .2 thus atleast 6 correct means P(6)*P(7)*P(*P(9)*P(10)
student : so at least 6 would be .2*.2*.2*.2*.2*.2=.000064 right?
tutor3 : yes it would be that
tutor3 : it was a silly mistake by me. thanks for the correction
student : haha i thought you just wanted me to figure it out on my own but seeing you did there helped me figure it out
tutor3 : ok great
student : A class is given a surprise 10 question multiple choice quiz over material they were supposed to study. Since none of the students are prepared, they are forced to guess the answers. The probability that a guess on any question is right is 20%.

Find the mean number of correct guesses for this 10 question quiz.
tutor3 : Please note, due to lack of resources, we can only do 1 problem FREE in 24 hours period. You can always come back tomorrow for another free problem. Please, tell your friends about our free service - 1 free in 24 hours

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