help!!!

Quote:

how to calculate the probability of randomly guessing the given number of correct answers on a 30 question multiple choice exam that has 4 choices

the probability of answering any single question correctly by chance is 1/4.

This is the p of a binomial distribution for the number of correctly answered questions.

Pr[correctly answering k questions out of 30] =

just replace p with 0.25 in the formula above.

bob1234567878787:

how to calculate the probability of randomly guessing the given number of correct answers on a 30 question multiple choice exam that has 4 choices

30Cn * 0.25 ⁿ * 0.75 ^30-n

where n is the number of correct guesses.

That is exactly what Rom said only he gave the explanation