(i)Marks given for one correct answer = 3
Marks given for 12 correct answers = 3 x 12 = 36 Radhika scored 20 marks.
Therefore, Marks obtained for incorrect answers = 20 – 36 = – 16
Now, marks given for one incorrect answer = –2
Therefore, number of incorrect answers = (-16) /(-2) = 8
Thus, Radhika has attempted 8 incorrect questions.
(ii) Marks given for seven correct answers = 3 x 7 = 21 Mohini scores = –5
Marks obtained for incorrect answers = –5 – 21 = – 26 Now, marks given for one incorrect answer = –2
Therefore, number of incorrect answers = (-26)/(-2) = 13
13 Thus, Mohini has attempted 13 incorrect questions.