Pierre attempted all the 29 questions in a quiz and scored 19 marks. Given that 5 marks were awarded for each correct answer but 2 marks were deducted for each wrong answer. how many questions did Pierre answer correctly?
Number of
correct answers |
Marks
awarded |
Number of
wrong answers |
Marks
deducted |
Total
marks |
29
|
29 x 5
= 145 |
0 |
0 |
145 |
28
|
28 x 5
= 140 |
1 |
1 x 2
= 2 |
140 - 2
= 138 |
| 11 |
11 x 5
= 55 |
18 |
18 x 2
= 28 |
55 - 28
= 19 |
Total marks awarded if all the answers are correct
= 29 x 5
= 145
Big difference in marks deducted
= 145 - 19
= 126
Small difference in marks deducted
= 5 + 2
= 7
Number of wrong answers
= 126 ÷ 7
= 18
Number of correct answers
= 29 - 18
= 11
Answer(s): 11
