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 1 mark is deducted from total score of correct answers if a candidate scored 450 marks in the test how many questions did he answered correctly​

Answer 1

Step-by-step explanation:

●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