Question

There are 90 multiple choice questions in a test . Suppose you get two marks for every correct answer and for every wrong or unattended question you get -1 mark. If you get 60 marks in the test than how many Anwer were correct.

Answer 1

Total 50 Answer are correct.

Explanation :-

2 mark for 1 Correct Question

Then if 50 question correct, then you gain = 50*2 = 100 marks.

-1 mark for every wrong question

Then The remaining 40 will be wrong

= 40*-1 = - 40

Then Correct Question Marks - Wrong Question Marks = Secured Marks

= 100 - 40 = 60

So The correct question is must be 50.

Answer 2

Answer:

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Suppose the no. of correctly answered questions be 'x', then no. of wrongly answer questions = 90-x.

It is given that for every correct answer 2 mrks are answered.

No. of marks scored for correct answers:- 2x

And it is given that for every wrongly answered questions '1' mark is deducted.

No. of marks to be deducted from the score =

= (90x - x) × 1 = 90 - x

Total score = 2x-(90-x) = 2x - 90 + x = 3x - 90

But it is given that total score is 60.

$3x - 90 = 60 \\ 3x = 60 + 90 \\ 3x = 150 \\ x = \frac{150}{3} = 50$

No. of questions answered Crctly = x = 50.