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Q.6 In a class test (+3) marks are given for every correct answer and (-2) marks are given for every incorrect answer and no marks for not attempting any question:
(i) Radhika scored 20 marks. If she has got 12 correct answers, how many questions has she attempted incorrectly?
(ii) Mohini scores -5 marks in this test, though she has got 7 correct answers. How many questions has she attempted incorrectly?
Answer :

Given that:
+3 marks are given for each correct answer. (-2) marks are given for each incorrect answer. Zero marks for not attempted questions.
(i) Radhika scored 20 marks Then, Total marks awarded for 12 correct answers = 12 × 3 = 36
Marks awarded for incorrect answers = Total score – Total marks awarded for 12 correct Answers = 20 – 36 = – 16
So, the number of incorrect answers made by Radhika = (-16) ÷ (-2) = 8

(ii) Mohini scored -5 marks Then, Total marks awarded for 7 correct answers = 7 × 3 = 21
Marks awarded for incorrect answers = Total score – Total marks awarded for 7 correct Answers = -5 - 21 = -26
So, the number of incorrect answers made by Radhika = (-26) ÷ (-2) = 13