Adam scores a total of 91 marks.
There are a total of 39 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
|
39 |
39 x 5 = 195 |
0 |
0 |
195 - 0 = 195 |
38 |
38 x 5 = 190 |
1 |
1 x 3 = 3 |
190 - 3 = 187 |
26 |
130 |
13 |
13 x 3 = 39 |
130 - 39 = 91 |
(a)
Total score if Adam answers all the questions correctly
= 39 x 5
= 195
Total score if Adam answers one question wrongly
= 190 - 3
= 187
Big difference in total score
= 195 - 91
= 104
Small difference in total score
= 5 + 3
= 8
Number of questions answered incorrectly
= 104 ÷ 8
= 13
(b)
Number of questions answered correctly
= 39 - 13
= 26
Answer(s): (a) 13; (b) 26