Q. 1324.3( 10 Votes )

# In a test, +3 marks are given for every correct answer and –1 mark are given for every incorrect answer. Sona attempted all the questions and scored +20 marks though she got 10 correct answers.

(i) How many incorrect answers has she attempted?

(ii) How many questions were given in the test?

Answer :

Given that, score of Sona = 20

Correct answers by Sona = 10

Sona attempted all question.

The score on 1 correct answer = 3

The score on 1 incorrect answer = -1

(i). Let number of incorrect answers attempted = x

So, we can say that

Sona’s total score = 3 × (Correct answer) + (-1) × (Incorrect answer)

⇒ 20 = 3 × 10 + (-1) × y

⇒ 20 = 30 – y

⇒ y = 30 – 20

⇒ y = 10

Thus, incorrect answers she attempted were 10.

(ii). Sona attempted each and every question in the test.

Correct answers = 10

Incorrect answers = 10

Total questions in the test = Total questions attempted by Sona

⇒ Total questions in the test = Correct answers + Incorrect answers

⇒ Total questions in the test = 10 + 10

⇒ Total questions in the test = 20

Thus, questions in the test = 20

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