Question

In a test, 5 marks are given for every correct answer and (-2) marks are given for every incorrect answer. 1) Anjali scored 30 mark. If she got 10 correct answers, how many questions she answered incorrectly? 2) Rohan got 4 correct answers. If he scored (-12) marks in the test, how many questions he answered incorrectly?

Answer 1

1. Anjali answered 10 questions incorrectly

2. Rohan answered 16 questions incorrectly

Explanation:

1 .The mark given for one correct answer = 5

That means that the mark given for 10 correct answers = 5 × 10 = 50

But Anjali's score = 30

Also, the marks gotten for incorrect answers = 30 - 50 = -20

Mark given for one incorrect answer = -2.

Therefore, number of incorrect answers would be;

= (-20) ÷ (-2)

= 10

•Anjali answered 10 questions incorrectly.

2. Total marks = -12

Number of correct answers = 4

Total marks for correct answers = 4 × 5 = 20

Also, marks for incorrect answers = -2 × Number of incorrect answers

Therefore,

Total marks = Marks for the correct answers + Marks for the incorrect answer

-12 = 20 + (-2) × Number of incorrect answers

-12 - 20 = -2 × Number of incorrect answers

-32 / 2 = Number of incorrect answers

Number of incorrect answers = 16

• Rohan answered 16 questions incorrectly.