Adam scores a total of 99 marks.
There are a total of 38 questions.
Every correct answer will earn 5 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
|
38 |
38 x 5 = 190 |
0 |
0 |
190 - 0 = 190 |
37 |
37 x 5 = 185 |
1 |
1 x 2 = 2 |
185 - 2 = 183 |
25 |
125 |
13 |
13 x 2 = 26 |
125 - 26 = 99 |
(a)
Total score if Adam answers all the questions correctly
= 38 x 5
= 190
Total score if Adam answers one question wrongly
= 185 - 2
= 183
Big difference in total score
= 190 - 99
= 91
Small difference in total score
= 5 + 2
= 7
Number of questions answered incorrectly
= 91 ÷ 7
= 13
(b)
Number of questions answered correctly
= 38 - 13
= 25
Answer(s): (a) 13; (b) 25