The number of incorrect answers made by Radhika is 8; the number of incorrect answers made by Mohini = 13
How to solve algebra word problems?
We are given;
Marks obtained for 1 right answer = +3
Marks obtained for 1 wrong answer = −2
(i) Marks scored by Radhika = 20
Marks obtained for 12 correct answers = 12 × 3 = 36
Marks obtained for incorrect answers = Total score − Marks obtained for 12 correct answers = 20 − 36 = −16
Marks obtained for 1 wrong answer = −2
Thus, number of incorrect answers = (−16) ÷(−2) = 8
Therefore, the number of incorrect answers made by Radhika = 8
(ii) Marks scored by Mohini = −5
Marks obtained for 7 correct answers = 7 × 3 = 21
Marks obtained for incorrect answers = Total score − Marks obtained for 12 correct answers = − 5 − 21 = −26
Marks obtained for 1 wrong answer = −2
Thus, number of incorrect answers = (−26) ÷ (−2) = 13
So, the number of incorrect answers made by Mohini = 13
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