Question

In a test, +4 marks are given for every correct answer and –1 mark are given for every incorrect answer. Ravi attempted all the questions and scored +30 marks though he got 10 correct answers.How many incorrect answers has he attempted?

5
10
20
15

Answer 1

Answer:

10

Step-by-step explanation:

Let the number of incorrect answers be x

Since we know that Ravi answered 10 questions correctly, then he should have got 4×10 = 40 marks. However, he got 30 marks.

This is due to the negative marks because of his incorrect answers. The total negative marks will be (-1)×x = -x

Total marks = Positive marks + negative marks

30 = 40 + (-x)

30 = 40-x

x = 10