Adam scores a total of 90 marks.
There are a total of 30 questions.
Every correct answer will earn 4 marks.
Every blank or wrong answer will have 2 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
|
30 |
30 x 4 = 120 |
0 |
0 |
120 - 0 = 120 |
29 |
29 x 4 = 116 |
1 |
1 x 2 = 2 |
116 - 2 = 114 |
25 |
100 |
5 |
5 x 2 = 10 |
100 - 10 = 90 |
(a)
Total score if Adam answers all the questions correctly
= 30 x 4
= 120
Total score if Adam answers one question wrongly
= 116 - 2
= 114
Big difference in total score
= 120 - 90
= 30
Small difference in total score
= 4 + 2
= 6
Number of questions answered incorrectly
= 30 ÷ 6
= 5
(b)
Number of questions answered correctly
= 30 - 5
= 25
Answer(s): (a) 5; (b) 25