SOLUTION: On a 5 question true or false test what is the probability of getting two right if you guess

Algebra ->  Probability-and-statistics -> SOLUTION: On a 5 question true or false test what is the probability of getting two right if you guess      Log On


   

Question 1135998: On a 5 question true or false test what is the probability of getting two right if you guess
Answer by greenestamps(13209) About Me  (Show Source):
You can put this solution on YOUR website!


The probability of choosing either the right or wrong answer on each question is 1/2.

The number of ways of choosing 2 of the 5 questions to be the ones that are answered correctly is "5 choose 2" = (5*4)/(2*1) = 10.

The total number of ways to answer the 5 questions is 2^5 = 32.

The probability of getting 2 of the 5 right is 10/32 = 5/16.