LINEAR EQUATIONS INTWO VARIABLES - CASE STUDY 1

A test consists of ‘True’ or ‘False’ questions.
One mark is awarded for every correct answer while ¼ mark is deducted for every wrong answer.

Type of Question: True / False
Marks given for correct answer: 1
Marks deducted for wrong answer: 0.25

A student knew answers to some of the questions. Rest of the questions he attempted by guessing.

He answered 120 questions and got 90 marks.

Question 1 of 4

If answer to all questions he attempted by guessing were wrong, then how many questions did he answer correctly?