Adam scores a total of 57 marks.
There are a total of 40 questions.
Every correct answer will earn 3 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
|
40 |
40 x 3 = 120 |
0 |
0 |
120 - 0 = 120 |
39 |
39 x 3 = 117 |
1 |
1 x 4 = 4 |
117 - 4 = 113 |
31 |
93 |
9 |
9 x 4 = 36 |
93 - 36 = 57 |
(a)
Total score if Adam answers all the questions correctly
= 40 x 3
= 120
Total score if Adam answers one question wrongly
= 117 - 4
= 113
Big difference in total score
= 120 - 57
= 63
Small difference in total score
= 3 + 4
= 7
Number of questions answered incorrectly
= 63 ÷ 7
= 9
(b)
Number of questions answered correctly
= 40 - 9
= 31
Answer(s): (a) 9; (b) 31