Adam scores a total of 33 marks.
There are a total of 20 questions.
Every correct answer will earn 3 marks.
Every wrong answer will earn 0 marks.
How many questions are (a) incorrectly answered and (b) correctly answered?
Number of correct answers |
Marks earned |
Number of incorrect answers |
Total marks |
20 |
20 x 3 = 60 |
0 |
60 |
19 |
19 x 3 = 57 |
1 |
57 |
11 |
11 x 3 = 33 |
9 |
33 |
(a)
Total score if Adam answers all the questions correctly
= 20 x 3
= 60
Total score if Adam answers one question wrongly
= 19 x 3
= 57
Big difference in marks deducted
= 60 - 33
= 27
Small difference in marks deducted
= 60 - 57
= 3
Number of questions answered incorrectly
= 27 ÷ 3
= 9
(b)
Number of questions answered correctly
= 20 - 9
= 11
Answer(s): (a) 9; (b) 11