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?

Question

anonymous · Answer

assumeing that 15 correct ans...

anonymous · Answer

she got 14 right
3 wrong

and skipped 3

anonymous · Answer

this makes total score of 67 :D

anonymous · Answer

good logic @hashsam1

anonymous · Answer

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

marco26 · Answer

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,,:)

anonymous · Answer

@marco26  can you solve that for us? :P

marco26 · Answer

this is consistent with hashsam1 's answer

marco26 · Answer

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