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 answered questions be $x$.
• Let the wrongly answered questions be $y$.

Then,according to the question,

$x+y=180$ and $4x-y=450$

Adding these two equations,

$x+y+4x-y=450+180$

$5x=630$

$x=126$

From the above equation,

$126+y=180$

$y=54$

Therefore, $126$ questions are answered correctly