Charlie attempted all the 28 questions in a quiz and scored 10 marks. Given that 9 marks were awarded for each correct answer but 2 marks were deducted for each wrong answer. how many questions did Charlie answer correctly?
Number of
correct answers |
Marks
awarded |
Number of
wrong answers |
Marks
deducted |
Total
marks |
28
|
28 x 9
= 252 |
0 |
0 |
252 |
27
|
27 x 9
= 243 |
1 |
1 x 2
= 2 |
243 - 2
= 241 |
| 6 |
6 x 9
= 54 |
22 |
22 x 2
= 27 |
54 - 27
= 10 |
Total marks awarded if all the answers are correct
= 28 x 9
= 252
Big difference in marks deducted
= 252 - 10
= 242
Small difference in marks deducted
= 9 + 2
= 11
Number of wrong answers
= 242 ÷ 11
= 22
Number of correct answers
= 28 - 22
= 6
Answer(s): 6
