Class 7 NCERT Solutions Maths Chapter 1 - Integers
Integers Exercise Ex. 1.1
Solution 1
Solution 2
Solution 3
Solution 4
Integers Exercise Ex. 1.2
Solution 1
Solution 2
Solution 3
Solution 4
Integers Exercise Ex. 1.3
Solution 1
Solution 2
Solution 3
Solution 4
Solution 5
Solution 6
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 answer = 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
So, she attempted 8 questions wrongly.
(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, she attempted 13 questions wrongly.