The same 20 contestants, on each of 3 days, answered 5 questions in order to win a prize. Each contestant received 1 point for each correct answer. The number of contestants receiving a given score on each day is shown in the table above.
What was the mean score of the contestants on Day 1 ?

The same 20 contestants, on each of 3 days, answered 5 questions in order to win a prize. Each contestant received 1 point for each correct answer. The number of contestants receiving a given score on each day is shown in the table above. No contestant received the same score on two different days. If a contestant is selected at random, what is the probability that the selected contestant received a score of 5 on Day 2 or Day 3, given that the contestant received a score of 5 on one of the three days?

The raw score on a certain standardized test is determined by subtracting 1/4 of the number of incorrect answers from the number of correct answers. IF a student answered 30 question and received a raw score of 20, how many question did the student answer incorrectly?

In a test, 1 mark is awarded for each correct answer and one mark is deducted for each wrong answer. If a boy answer all 20 items of the test and gets 8 marks, the number of questions answered correct by him was

On a 26 question test, five points were deducted for each wrong answer and eight points were credited for each correct answer. If all the questions were answered, how many were correct if the score was zero? (a) 6 (b) 9 (c) 10 (d) 13