Answer: 20
Explanation:
(i) Sona got 10 answers correct.
1 correct answer = 3 marks
10 correct answers = 10×3 = 30 marks but she got only 20
1 wrong answer = -1 mark
that means she attempted 10 incorrect answers.
No.of questions in the test= no.of incorrect + no.of correct answers
10+10= 20