Question

In a test +3 are given for every correct answer and -1 mark 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 1

Step-by-step explanation:

let the number of questions sona attempted incorrectly be x.

sona's score =20.

10 questions×3 marks+x×(-2)marks =20.

30+(-2x)=20

30-20=2x (by transposing).

10=2x

10/2=x

5=x.

therefre she attept 5 questions incorrectly.

number of questions given in the test = number of questions sona attempted incorrectly +number of questions sona attempted correctly.

=10 + 5 .

= 15.

therefore there is 15 questions in examination.

hope it helps you.