## pythagoras123 3 years ago There are 20 questions in a quiz. 5 marks are awarded for each correct answer, 2 marks are deducted for each wrong answer and 1 mark was awarded if the question was not attempted. Sophia got 67 marks altogether. How many questions did she get correct?

1. Eric_Playsinacoolway

assumeing that 15 correct ans...

2. hashsam1

she got 14 right 3 wrong and skipped 3

3. hashsam1

this makes total score of 67 :D

4. Eric_Playsinacoolway

good logic @hashsam1

5. hashsam1

14*5=70 right answers 3*2=6 wrong ones 70-6=64 as she had skipped 3 thus she was awarded 3 marks her total score 64+3=67 Thanks

6. marco26

Hmm, I guess this is the equation ,, :) not sure, though 5x + y -2z = 67 x + y + z = 20 Let x be the no. of correct answer, y be the skiipped answer, z be the wrong no...and solve,,:)

7. hashsam1

@marco26 can you solve that for us? :P

8. marco26

this is consistent with hashsam1 's answer

9. marco26

lol,, this can be done by gauss jordan reduction, or any convenient method,..anyway, the answer is already there :)