Question

in an examination if a student looses mark for the wrong answer and get 1 mark for correct answer if he got 30 mark for solving 54 que. then how many que. were correct?

Answer 1

there could be many possibilities of getting 30 outta 54

Answer 2

R-W=30
R+W=54

add these equations together

2R=...
R=...

R+W=54
W=...

Answer 3

ghazi i think 54 was the number of questions attempted , the examination probably had more questions than this

Answer 4

you sure... :) ? that's why i wrote many possibilities also what if marks deducted for one wrong answer is not exactly 1 , what is for one wrong question it is 0.25 or 0.50

Answer 5

*if

Answer 6

The last thing that @rajmscrewa wrote on the previous post was that each wrong answer was one point.

Answer 7

ok solve all possibilities

Answer 8

@UnkleRhaukus gave a good method for solving above. It leads to one possibility.

Answer 9

yea agreed...for one negative..it's just one answer

Answer 10

ok if he looses 0.50 marks for a wrong answer than

Answer 11

I thought about that a little already...
I think that it would start:
R-0.5W=30
R+W=54
Where R is number correct and W is number incorrect.

Answer 12

than

Answer 13

if he looses 0.25 marks

Answer 14

I'm not sure I'm right... it doesn't seem to work out.

Answer 15

' student looses mark '
this is singular tense even if there is a word missing

Answer 16

Wait, yeah it worked.

It becomes formulaic.
(weight for correct)R-(weight for incorrect)W=score
R+W=(number of questions)