Question

There are 180 multiple choice questions in a test. A candidate gets 4 marks for every
correct answer, and for every un-attempted or wrongly answered questions one mark is
deducted from the total score of correct answers. If a candidate scored 450 marks in the
test how many questions did he answer correctly?​

Answer 1

let the number of correctly attempted questions be x

so, the number of unattempeted or wrong question = 180-x

total marks for correct attemptions = 4x

and total marks for unattempeted or wrong question = -1 (180-x)

= x - 180

as total marks = sum of attempted and unattempeted or wrong question = 180-x

450 = 4x + x - 180

450 = 5x -180

630 = 5x

126 = x

so, the number of correctly attempted question was 126.

Answer 2

please refer pic above