Question

What is the chance of getting 50/% correct on a test with 20 questions, each question is either True or False. Assume you are blindly guessing and answer all questions

Answer 1

I will read that as you want to get exactly 50% correct, if you mean at least 50% then it would be a long tedious calculation.

prob of (10 of 20 correct)
= C(20,10) (1/2)^10 (1/2)^10
= 184756 ( 1/2^20)
= appr .1762

Answer 2

adf