Question

In a competitive examination, one mark is awarded for every correct answer while 1/4 mark is deducted for every wrong answer. A student answered 100 questions and got 80 marks. How
many questions did he answer correctly ? (Use Cramer’s rule to solve the problem).

Answer 1

84 questions he answered is correct and he get 84 marks and 16 questions he answered is wrong and get - 4 marks. So total marks he get is 80.