Question

Colin predicted whether he got answers right or wrong in his 50 question exam.

He identified the 12 questions he thought he got wrong.
It turns out that Colin got 5 questions right that he thought he got wrong.
Colin also got a total score of 42 out of 50 in the test.
What is the percentage accuracy he had with predicting his scores

Answer 1

92.86%

Explanation:

Total questions, T = 50.

Colin thought 8 questions were right.

Colin got 5 questions right that he thought he got wrong.

Total score, s = 45.

So, actual number of questions which are wrong are 5.

Score according to him = 50 - 8 = 42.

Now, we know percentage accuracy is given by :

Therefore, percentage accuracy he had with predicting his scores is 92.86%.