The probability that a student guesses the correct answer to a five -choice multiple choice question is P (correct) equals0.2. How many correct answers should a student expect to guess on a test with 70 five -choice multiple choice questions?

For each question we have 4 choices. So if you have 10 on such questions, you ll have:

4*4*4*4*4*4*4*4*4*4 = 4^10 = 2048

Getting 8 correct means=> 8 corrects and two wrongs

3/4 is the probability if a question is answered wrong

1/4 is the probability if a question is answered correctly

so we can consider this probability:

P = (3/4) * (3/4) * (1/4) * (1/4) * (1/4) * (1/4) * (1/4) * (1/4) * (1/4) * (1/4)

=> P=0.00000858306

But as we can select any combination of 2 from 10 for being wrong, so we need to multiply P by (10,2) = 10! / (2!*8!) = 45

so the answer is P*45 = 0.00038623809

So not very lucky to answer randomly!

By the way, is it a question from your home work assignment?; );

tbh google