Adam scores a total of 68 marks.
There are a total of 28 questions.
Every correct answer will earn 5 marks.
Every blank or wrong answer will have 4 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
|
28 |
28 x 5 = 140 |
0 |
0 |
140 - 0 = 140 |
27 |
27 x 5 = 135 |
1 |
1 x 4 = 4 |
135 - 4 = 131 |
20 |
100 |
8 |
8 x 4 = 32 |
100 - 32 = 68 |
(a)
Total score if Adam answers all the questions correctly
= 28 x 5
= 140
Total score if Adam answers one question wrongly
= 135 - 4
= 131
Big difference in total score
= 140 - 68
= 72
Small difference in total score
= 5 + 4
= 9
Number of questions answered incorrectly
= 72 ÷ 9
= 8
(b)
Number of questions answered correctly
= 28 - 8
= 20
Answer(s): (a) 8; (b) 20