Exercise 1D
Page-12Question 1:
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6 − (−8) = ?
(a) −2
(b) 2
(c) 14
(d) none of these
Answer 1:
(c) 14
Given:
6 − (−8)
= 6 + 8
= 14
RS Aggarwal 2019,2020 solution class 7 chapter 1 Integers Exercise 1D
Question 2:
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−9 − (−6) = ?
(a) −15
(b) −3
(c) 3
(d) none of these
Answer 2:
(b) −3
Given:
−9 − (−6)
= −9 + 6
= −3
Question 3:
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By how much does 2 exceed −3?
(a) −1
(b) 1
(c) −5
(d) 5
Answer 3:
(d) 5
We can see that
−3 + 5 = 2
Hence, 2 exceeds −3 by 5.
Question 4:
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What must be subtracted from −1 to get −6?
(a) 5
(b) −5
(c) 7
(d) −7
Answer 4:
(a) 5
Let the number to be subtracted be x.
To find the number, we have:
−1 − x = −6
∴ x = −1 + 6 = 5
Question 5:
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How much less than −2 is −6?
(a) 4
(b) −4
(c) 8
(d) −8
Answer 5:
(c) 4
We can see that
(−2) − (−6) = (−2) + 6 = 4
Hence, −6 is four (4) less than −2.
Question 6:
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On subtracting 4 from −4, we get
(a) 8
(b) −8
(c) 0
(d) none of these
Answer 6:
(b) −8
Subtracting 4 from −4, we get:
(−4) − 4 = −8
Question 7:
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By how much does −3 exceed −5?
(a) −2
(b) 2
(c) 8
(d) −8
Answer 7:
(b) 2
Required number = (−3) − (−5) = 5 − 3 = 2
Question 8:
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What must be subtracted from −3 to get −9?
(a) −6
(b) 12
(c) 6
(d) −12
Answer 8:
(c) 6
(−3) − x = −9
∴ x = (−3) + 9 = 6
Hence, 6 must be subtracted from −3 to get −9.
Question 9:
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On subtracting 6 from −5, we get
(a) 1
(b) 11
(c) −11
(d) none of these
Answer 9:
(c) −11
Subtracting 6 from −5, we get:
(−5) − 6 = −11
Question 10:
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On subtracting −13 from −8, we get
(a) −21
(b) 21
(c) 5
(d) −5
Answer 10:
(c) 5
Subtracting −13 from −8, we get:
(−8) − (−13)
= −8 + 13
= 5
Question 11:
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(−36) ÷ (−9) = ?
(a) 4
(b) −4
(c) none of these
Answer 11:
(a) 4
(−36) ÷ (−9) = 4
Here, the negative signs in both the numerator and denominator got cancelled with each other.
Question 12:
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0 ÷ (−5) = ?
(a) −5
(b) 0
(c) not defined
Answer 12:
(b) 0
Dividing zero by any integer gives zero as the result.
Question 13:
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(−8) ÷ 0 = ?
(a) −8
(b) 0
(c) not defined
Answer 13:
(c) not defined
Dividing any integer by zero is not defined.
Question 14:
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Which of the following is a true statement?
(a) −11 > −8
(b) −11 < −8
(c) −11 and −8 cannot be compared
Answer 14:
(b) −11 < −8
Negative integers decrease with increasing magnitudes.
Question 15:
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The sum of two integers is 6. If one of them is −3, then the other is
(a) −9
(b) 9
(c) 3
(d) −3
Answer 15:
(b) 9
Let the other integer be a. Then, we have:
−3 + a = 6
∴ a = 6 − (−3) = 9
Question 16:
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The sum of two integers is −4. If one of them is 6, then the other is
(a) −10
(b) 10
(c) 2
(d) −2
Answer 16:
(a) −10
Let the other integer be a. Then, we have:
6 + a = −4
∴ a = −4 − 6 = −10
Hence, the other integer is −10.
Question 17:
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The sum of two integers is 14. If one of them is −8, then the other is
(a) 22
(b) −22
(c) 6
(d) −6
Answer 17:
(a) 22
Let the other integer be a. Then, we have:
−8 + a = 14
∴ a = 14 + 8 = 22
Hence, the other integer is 22.
Question 18:
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The additive inverse of −6 is
(a)
(b)
(c) 6
(d) 5
Answer 18:
(c) 6
The additive inverse of any integer a is −a.
Thus, the additive inverse of −6 is 6.
Question 19:
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(−15) × 8 + (−15) × 2 = ?
(a) 150
(b) −150
(c) 90
(d) −90
Answer 19:
(b) −150
We have (−15) × 8 + (−15) × 2
= (−15) × (8 + 2) [Associative property]
= −150
Question 20:
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(−12) × 6 −(−12) × 4 = ?
(a) 24
(b) −24
(c) 120
(d) −120
Answer 20:
(b) −24
We have (−12) × 6 − (−12) × 4
= (−12) × (6 − 4) [Associative property]
= −24
Question 21:
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(−27) × (−16) + (−27) × (−14) = ?
(a) −810
(b) 810
(c) −54
(d) 54
Answer 21:
(b) 810
(−27) × (−16) + (−27) × (−14)
= (−27) × (−16 + (−14)) [Associative property]
=(−27) × (−30)
= 810
Question 22:
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30 × (−23) + 30 × 14 = ?
(a) −270
(b) 270
(c) 1110
(d) −1110
Answer 22:
(a) −270
30 × (−23) + 30 × 14
= 30 × (−23 + 14) [Associative property]
= 30 × (−9)
= −270
Question 23:
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The sum of two integers is 93. If one of them is −59, the other one is
(a) 34
(b) −34
(c) 152
(d) −152
Answer 23:
(c) 152
Let the other integer be a. Then, we have:
−59 + a = 93
∴ a = 93 + 59 = 152
Question 24:
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(?) ÷ (−18) = −5
(a) −90
(b) 90
(c) none of these
Answer 24:
(b) 90
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