Adam scores a total of 83 marks.
There are a total of 31 questions.
Every correct answer will earn 5 marks.
Every blank or wrong answer will have 3 marks deducted.
How many questions are (a) incorrectly answered and (b) correctly answered?
Number of correct answers |
Marks earned
|
Number of incorrect answers |
Marks deducted
|
Total score
|
31 |
31 x 5 = 155 |
0 |
0 |
155 - 0 = 155 |
30 |
30 x 5 = 150 |
1 |
1 x 3 = 3 |
150 - 3 = 147 |
22 |
110 |
9 |
9 x 3 = 27 |
110 - 27 = 83 |
(a)
Total score if Adam answers all the questions correctly
= 31 x 5
= 155
Total score if Adam answers one question wrongly
= 150 - 3
= 147
Big difference in total score
= 155 - 83
= 72
Small difference in total score
= 5 + 3
= 8
Number of questions answered incorrectly
= 72 ÷ 8
= 9
(b)
Number of questions answered correctly
= 31 - 9
= 22
Answer(s): (a) 9; (b) 22