Ethan attempted all the 22 questions in a quiz and scored 16 marks. Given that 9 marks were awarded for each correct answer but 4 marks were deducted for each wrong answer. how many questions did Ethan answer correctly?
Number of correct answers |
Marks awarded |
Number of wrong answers |
Marks deducted |
Total marks |
22
|
22 x 9 = 198 |
0 |
0 |
198 |
21
|
21 x 9 = 189 |
1 |
1 x 4 = 4 |
189 - 4 = 185 |
8 |
8 x 9 = 72 |
14 |
14 x 4 = 21 |
72 - 21 = 16 |
Total marks awarded if all the answers are correct
= 22 x 9
= 198
Big difference in marks deducted
= 198 - 16
= 182
Small difference in marks deducted
= 9 + 4
= 13
Number of wrong answers
= 182 ÷ 13
= 14
Number of correct answers
= 22 - 14
= 8
Answer(s): 8