Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers

Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers

Selina Publishers Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers

Integers Exercise 1A – Selina Concise Mathematics Class 7 ICSE Solutions

Question 1.
Evaluate:

  1. 427 x 8 + 2 x 427
  2. 394 x 12 + 394 x (-2)
  3. 558 x 27 + 3 x 558

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1A 1
Question 2.
Evaluate:

  1. 673 x 9 + 673
  2. 1925 x 101 – 1925

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1A 2

Question 3.
Verify:

  1. 37 x {8 +(-3)} = 37 x 8 + 37 x – (3)
  2. (-82) x {(-4) + 19} = (-82) x (-4) + (-82) x 19
  3. {7 – (-7)} x 7 = 7 x 7 – (-7) x 7
  4. {(-15) – 8} x -6 = (-15) x (-6) – 8 x (-6)

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1A 3
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1A 4
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1A 5

Question 4.
Evaluate:

  1. 15 x 8
  2. 15 x (-8)
  3. (-15) x 8
  4. (-15) x -8

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1A 6

Question 5.
Evaluate:

  1. 4 x 6 x 8
  2. 4 x 6 x (-8)
  3. 4 x (-6) x 8
  4. (-4) x 6 x 8
  5. 4 x (-6) x (-8)
  6. (-4) x (-6) x 8
  7. (-4) x 6 x (- 8)
  8. (-4) x (-6) x (-8)

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1A 7

Question 6.
Evaluate:

  1. 2 x 4 x 6 x 8
  2. 2 x (-4) x 6 x 8
  3. (-2) x 4 x (-6) x 8
  4. (-2) x (-4) X 6 x (-8)
  5. (-2) x (-4) x (-6) x (-8)

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1A 8

Question 7.
Determine the integer whose product with ‘-1’ is:

  1. -47
  2. 63
  3. -1
  4. 0

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1A 9
Question 8.
Eighteen integers are multiplied together. What will be the sign of their product, if:

  1. 15 of them are negative and 3 are positive?
  2. 12 of them are negative and 6 are positive?
  3. 9 of them are positive and the remaining are negative?
  4. all are negative?

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1A 10

Question 9.
Find which is greater?

  1. (8 + 10) x 15 or 8 + 10 x 15
  2. 12 x (6 – 8) or 12 x 6 – 8
  3. {(-3) – 4} x (-5) or (-3) – 4 x (-5)

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1A 11

Question 10.
State, true or false :

  1. product of two integers can be zero.
  2. product of 120 negative integers and 121 positive integers is negative.
  3. a x (b + c) = a x b + c
  4. (b – c) x a=b – c x a

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1A 12

Integers Exercise 1B – Selina Concise Mathematics Class 7 ICSE Solutions

Question 1.
Divide:
(i) 117 by 9
(ii) (-117) by 9
(iii) 117 by (-9)
(iv) (-117) by (-9)
(v) 225 by (-15)
(vi) (-552) ÷ 24
(vii) (-798) by (-21)
(viii) (-910) ÷ – 26

Solution :
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1B 13
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1B 14

Question 2.
Evaluate:
(i) (-234) ÷ 13
(ii) 234 ÷ (-13)
(iii) (-234) ÷ (-13)
(iv) 374 ÷ (-17)
(v) (-374) ÷ 17
(vi) (-374) ÷ (-17)
(vii) (-728) ÷ 14
(viii) 272 ÷ (-17)

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1B 15
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1B 16

Question 3.
Find the quotient in each of the following divisions:
(i) 299 ÷ 23
(ii) 299 ÷ (-23)
(iii) (-384) ÷ 16
(iv) (-572) ÷ (-22)
(v) 408 ÷ (-17)

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1B 53

Question 4.
Divide:
(i) 204 by 17
(ii) 152 by-19
(iii) 0 by 35
(iv) 0 by (-82)
(v) 5490 by 10
(vi) 762800 by 100

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1B 18

Question 5.
State, true or false :

  1. 0 ÷ 32 = 0
  2. 0 ÷ (-9) = 0
  3. (-37) ÷ 0 = 0
  4. 0 ÷ 0 = 0

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1B 19

Question 6.
Evaluate:
(i) 42 ÷ 7 + 4
(ii) 12+18 ÷ 3
(iii) 19 – 20 ÷ 4
(iv) 16 – 5 x 3+4
(v) 6 – 8 – (-6) ÷ 2
(vi) 13 -12 ÷ 4 x 2
(vii) 16 + 8 ÷ 4- 2 x 3
(viii) 16 ÷ 8 + 4 – 2 x 3
(ix) 16 – 8 + 4 ÷ 2 x 3
(x) (-4) + (-12) ÷ (-6)
(xi) (-18) + 6 ÷ 3 + 5
(xii) (-20) x (-1) + 14 – 7

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1B 20
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1B 21
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1B 22

Integers Exercise 1C – Selina Concise Mathematics Class 7 ICSE Solutions

Question 1.
Evaluate:
18-(20- 15 ÷ 3)
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1C 23

Question 2.
-15+ 24÷ (15-13)
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1C 24

Question 3.
35 – [15 + {14-(13 + \(\overline { 2-1+3 }\))}]
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1C 25

Question 4.
27- [13 + {4-(8 + 4 – \(\overline { 1+3 }\))}]
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1C 26

Question 5.
32 – [43-{51 -(20 – \(\overline { 18 -7 }\))}]
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1C 27

Question 6.
46-[26-{14-(15-4÷ 2 x 2)}]
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1C 28

Question 7.
45 – [38 – {60 ÷ 3 – (6 – 9 ÷ 3) ÷ 3}]
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1C 29

Question 8.
17- [17 — {17 — (17 – \(\overline { 17 -17 }\))}]
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1C 30

Question 9.
2550 – [510 – {270 – (90 – \(\overline { 80 + 7 }\))}]
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1C 31

Question 10.
30+ [{-2 x (25-\(\overline { 13 -3 }\))}]
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1C 32

Question 11.
88-{5-(-48)+ (-16)}
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1C 33

Question 12.
9 x (8-\(\overline { 3 +2 }\)) – 2 (2 + \(\overline { 3 +3 }\))
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1C 34

Question 13.
2 – [3 – {6 – (5 – \(\overline { 4 -3 }\))}]
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1C 35

Integers Exercise 1D – Selina Concise Mathematics Class 7 ICSE Solutions

Question 1.
The sum of two integers is -15. If one of them is 9, find the other.
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 36

Question 2.
The difference between an integer and -6 is -5. Find the values of x.
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 37

Question 3.
The sum of two integers is 28. If one integer is -45, find the other.
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 38

Question 4.
The sum of two integers is -56. If one integer is -42, find the other.
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 39

Question 5.
The difference between an integer x and (-9) is 6. Find all possible values ofx.
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 40
Question 6.
Evaluate:

  1. (-1) x (-1) x (-1) x  ….60 times.
  2. (-1) x (-1) x (-1) x (-1) x …. 75 times.

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 41
Question 7.
Evaluate:

  1. (-2) x (-3) x (-4) x (-5) X (-6)
  2. (-3) x (-6) x (-9) x (-12)
  3. (-11) x (-15) + (-11) x (-25)
  4. 10 x (-12) + 5 x (-12)

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 42

Question 8.

  1. If x x (-1) = -36, is x positive or negative?
  2. If x x (-1) = 36, is x positive or negative?

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 43
∴ It is a positive integer.

Question 9.
Write all the integers between -15 and 15, which are divisible by 2 and 3.
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 44

Question 10.
Write all the integers between -5 and 5, which are divisible by 2 or 3.
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 45

Question 11.
Evaluate:

  1. (-20) + (-8) ÷ (-2) x 3
  2. (-5) – (-48) ÷ (-16) + (-2) x 6
  3. 16 + 8 ÷ 4- 2 x 3
  4. 16 ÷ 8 x 4 – 2 x 3
  5. 27 – [5 + {28 – (29 – 7)}]
  6. 48 – [18 – {16 – (5 – \(\overline { 4 +1 }\))}]
  7. -8 – {-6 (9 – 11) + 18 = -3}
  8. (24 ÷ \(\overline { 12 -9 }\) – 12) – (3 x 8 ÷ 4 + 1)

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 46
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 47
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 48

Question 12.
Find the result of subtracting the sum of all integers between 20 and 30 from the sum of all integers from 20 to 30.
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 49

Question 13.
Add the product of (-13) and (-17) to the quotient of (-187) and 11.
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 50

Question 14.
The product of two integers is-180. If one of them is 12, find the other.
Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 51

Question 15.

  1. A number changes from -20 to 30. What is the increase or decrease in the number?
  2. A number changes from 40 to -30. What is the increase or decrease in the number?

Solution:
Selina Concise Mathematics Class 7 ICSE Solutions Chapter 1 Integers Ex 1D 52

Selina Concise Mathematics Class 7 ICSE Solutions

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