Q162
ArithmeticNumber System, LCM/HCF & Divisibility
There are 100 questions in a question paper, each carrying 2 marks. But there is a negative marking. 1 mark is deducted for each question answered incorrectly. A student answering all the questions got 80 marks. The number of questions correctly answered by him is
- a.70.
- b.60.
- c.80.
- d.75.
Answer: (B) 60.
Let correct = x, incorrect = 100−x. Marks = $2x − (100−x) = 3x − 100 = 80$. So $3x = 180$, $x = 60$.