NCERT Exemplar Solutions
Class 7 - Mathematics - Unit 4: Simple Equations
Fill in the Blanks

In Questions 19 to 48, fill in the blanks to make the statements true.

Question. 19

19. The sum of two numbers is 60 and their difference is 30.

(a) If smaller number is x, the other number is ________ (use sum).

(b) The difference of numbers in term of x is ________.

(c) The equation formed is ________.

(d) The solution of the equation is ________.

(e) The numbers are ________ and ________.

Answer:

(a) 60 − x

(b) 60 − 2x

(c) −2x = −30

(d) 15

(e) 45 and 15

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Question. 20

20. Sum of two numbers is 81. One is twice the other.

(a) If smaller number is x, the other number is ________.

(b) The equation formed is ________.

(c) The solution of the equation is ________.

(d) The numbers are ________ and ________.

Answer:

(a) 2x

(b) x + 2x = 81

(c) 27

(d) 54 and 27

Open

Question. 21

21. In a test Abha gets twice the marks as that of Palak. Two times Abha's marks and three times Palak's marks make 280.

(a) If Palak gets x marks, Abha gets ________ marks.

(b) The equation formed is ________.

(c) The solution of the equation is ________.

(d) Marks obtained by Abha are ________.

Answer:

(a) 2x

(b) 4x + 3x = 280

(c) 40

(d) 80

Open

Question. 22

22. The length of a rectangle is two times its breadth. Its perimeter is 60 cm.

(a) If the breadth of rectangle is x cm, the length of the rectangle is ________.

(b) Perimeter in terms of x is ________.

(c) The equation formed is ________.

(d) The solution of the equation is ________.

Answer:

(a) 2x

(b) 6x or 2(2x + x)

(c) 6x = 60

(d) 10

Open

Question. 23

23. In a bag there are 5 and 2 rupee coins. If they are equal in number and their worth is ₹70, then

(a) The worth of x coins of ₹5 each ________.

(b) The worth of x coins of ₹2 each ________.

(c) The equation formed is ________.

(d) There are ________ 5 rupee coins and ________ 2 rupee coins.

Answer:

(a) ₹5x

(b) ₹2x

(c) 5x + 2x = 70

(d) 10, 10

Open

Question. 24

24. In a Mathematics quiz, 30 prizes consisting of 1st and 2nd prizes only are to be given. 1st and 2nd prizes are worth ₹2000 and ₹1000, respectively. If the total prize money is ₹52,000 then show that:

(a) If 1st prizes are x in number the number of 2nd prizes are ________.

(b) The total value of prizes in terms of x are ________.

(c) The equation formed is ________.

(d) The solution of the equation is ________.

(e) The number of 1st prizes are ________ and the number of 2nd prizes are ________.

Answer:

(a) 30 − x

(b) 2000x + 1000(30 − x)

(c) 1000x + 30000 = 52000

(d) 22

(e) 22, 8

Open

Question. 25

If z + 3 = 5, then z = ________.

Answer:

If z + 3 = 5, then z = 2.

Open

Question. 26

________ is the solution of the equation 3x − 2 = 7.

Answer:

x = 3 is the solution.

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Question. 27

________ is the solution of 3x + 10 = 7.

Answer:

x = −1 is the solution.

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Question. 28

If 2x + 3 = 5, then value of 3x + 2 is ________.

Answer:

5

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Question. 29

In integers, 4x − 1 = 8 has ________ solution.

Answer:

No solution.

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Question. 30

In natural numbers, 4x + 5 = −7 has ________ solution.

Answer:

No solution.

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Question. 31

In natural numbers, x − 5 = −5 has ________ solution.

Answer:

No solution.

Open

Question. 32

In whole numbers, x + 8 = 12 − 4 has ________ solution.

Answer:

One solution.

Open

Question. 33

If 5 is added to three times a number, it becomes the same as 7 is subtracted from four times the same number. This fact can be represented as ________.

Answer:

3x + 5 = 4x − 7

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Question. 34

x + 7 = 10 has the solution ________.

Answer:

x = 3

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Question. 35

x − 0 = ________; when 3x = 12.

Answer:

4

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Question. 36

x − 1 = ________; when 2x = 2.

Answer:

0

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Question. 37

x − ________ = 15; when x/2 = 6.

Answer:

−3

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Question. 38

The solution of the equation x + 15 = 19 is ________.

Answer:

4

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Question. 39

Finding the value of a variable in a linear equation that ________ the equation is called a ________ of the equation.

Answer:

Finding the value of a variable in a linear equation that satisfies the equation is called a root of the equation.

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Question. 40

Any term of an equation may be transposed from one side of the equation to the other side of the equation by changing the ________ of the term.

Answer:

sign

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Question. 41

If 9/5 x = 18/5, then x = ________.

Answer:

2

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Question. 42

If 3 − x = −4, then x = ________.

Answer:

7

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Question. 43

If x − 1/2 = −1/2, then x = ________.

Answer:

0

Open

Question. 44

If 1/6 − x = 1/6, then x = ________.

Answer:

0

Open

Question. 45

If 10 less than a number is 65, then the number is ________.

Answer:

75

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Question. 46

If a number is increased by 20, it becomes 45. Then the number is ________.

Answer:

25

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Question. 47

If 84 exceeds another number by 12, then the other number is ________.

Answer:

72

Open

Question. 48

If x − 7/8 = 7/8, then x = ________.

Answer:

7/4

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NCERT Exemplar Solutions Class 7 – Mathematics – Unit 4: Simple Equations – Fill in the Blanks | Detailed Answers