In an examination if a student looses mark for the wrong answer and gets 1 mark for the correct answer. If he got 30 marks for solving54 questions, then how many questions were correct?

Question

anonymous · Answer

how many mark lose for wrong answer?

anonymous · Answer

not mentioned in the question

anonymous · Answer

I'd say 12 wrong, 42 right.

anonymous · Answer

@ParthKohli need help

anonymous · Answer

how did u get that

anonymous · Answer

yap, 42 right and 12 wrong; if wrong answer deduct 1 mark each

anonymous · Answer

x - y = 30
x + y = 54

x - 30 = y
x + (x - 30) = 54
2x - 30 = 54
2x = 84
x = 42

42 - 30 = 12

parthkohli · Answer

If there are x right, then 54 - x are wrong.

1(x) + -1(54 - x) = 30
x + (-54 + x) = 30
x - 54 + x = 30
2x - 54 = 30
2x = 84
x = 42

x are right, so 42 are right.
54 - x are wrong, 54 - 42 = 12 are wrong.

parthkohli · Answer

Get it, @Pratika_Rathore >

anonymous · Answer

No actually the ans. is not matching it is given as 36 and i don't know that fr mwhere the hell that 36 came...because at first i did the same ...

parthkohli · Answer

How many marks are deducted on a wrong answer?

anonymous · Answer

Not mentioned...

parthkohli · Answer

If the student loses a mark, then he/she loses one mark.

parthkohli · Answer

(42 * 1) + (12 * -1) 
42 - 12
30

Answer is correct..

anonymous · Answer

if 1 marks is deducted for every three wrong answer, then you can get 36 right answer

parthkohli · Answer

Or, 1/3 deducted for a wrong one..

anonymous · Answer

thanx