Class 8 Maths Chapter 2 Linear Equations in One Variable MCQs

Class 8 Maths Chapter 2  Linear Equations in One Variable MCQs (Questions and Answers) are available online here for students. These objective questions are designed as per the CBSE board syllabus (2022-2023) and NCERT guidelines. The chapter-wise questions are provided here for students to make them understand each concept and help to score better marks in exams. Also, learn important questions for class 8 Maths here at BYJU’S.

Practice more and test your skills on Class 8 Maths Chapter 2 Linear Equations in One Variable MCQs with the given PDF here.

MCQs on Class 8 Linear Equations in One Variable

Multiple choice questions (MCQs) are available for Class 8 Linear Equations in One Variable with each problem consisting of four options, out of which one is the correct answer. Students have to solve the problem and select the correct answer. Verify your solution with the answers provided here.

1. Which of the following is not a linear equation in one variable?

A. 33z+5 = 0

B. 33(x+y) = 0

C. 33x+5 = 0

D. 33y+5 = 0

Answer: B

Explanation: In 33(x+y) = 0, x and y are two variables.

2. The solution of 2x-3=7 is:

A. 5

B. 7

C. 12

D. 11

Answer: A

Explanation: 2x-3=7

2x=7+3=10

x=10/2 = 5

3. The solution of 2y + 9 = 4 is:

A. 9/2

B. 4/9

C. -⅖

D. -5/2

Answer: D

Explanation: 2y+9 = 4

2y = 4-9 = -5

y=-5/2

4. The solution of y/5 = 10 is:

A. 15

B. 10

C. 50

D. 5

Answer: C

Explanation: y/5 = 10

y = 5×10 = 50

5. What should be added to -7/3 to get 3/7?

A. 21/58

B. 58/21

C. 47/21

D. 50/21

Answer: B

Explanation: Let the number be x

-7/3+x = 3/7

x=3/7+7/3 = (9+49)/21 = 58/21

6. The perimeter of the rectangle is 20cm. If the length of the rectangle is 6cm, then its breadth will be:

A. 4 cm

B. 6 cm

C. 10 cm

D. 14 cm

Answer: A

Explanation: Perimeter of rectangle = 2(Length+Breadth)

20 = 2(6+x)

6+x = 20/2

6+x = 10

x = 10-6

x=4 cm

7. The age of the father is three times the age of the son. If the age of the son is 15 years old, then the age of the father is:

A. 50 years

B. 55 years

C. 40 years

D. 45 years

Answer: D

Explanation: Let the age of the father is x

Given: x = 3 × (age of son) = 3 × (15) = 45 years

8. The difference between two whole numbers is 66. The ratio of the two numbers is 2: 5. The two numbers are:

A. 60 and 6

B. 100 and 33

C. 110 and 44

D. 99 and 33

Answer: C

Explanation: Let the two numbers be 2x and 5x since they are in the ratio of 2:5.

The difference between 5x and 2x = 66

5x – 2x = 66

3x = 66

x = 22

Hence, 2x = 2(22) = 44 and 5x = 5(22) = 110.

9. Three consecutive integers add up to 51. The integers are:

A. 16,17,18

B. 15,16,17

C. 17,18,19

D. 18,19,20

Answer: A

Explanation: Let the three consecutive integers be x, x+1, x+2

x+(x+1)+(x+2) = 51

3x+3 = 51

3x = 51 – 3

x = 48/3 = 16

x+1 = 16+1=17

x+2 = x+2 = 18

10. The solution for 3m = 5m – (8/5) is:

A. 8/5

B. ⅘

C. 5/4

D. 4/3

Answer: B

Explanation: 3m = 5m – (8/5)

8/5 = 5m – 3m

2m = 8/5

m = 8/10 = 4/5

11. The degree of x² – 5x + 2 = x³ is:

A. 3
B. 2
C. 1
D. 0

Answer: A. 3

Explanation: Degree is the highest power of the variable in an equation. Therefore, in the given equation, the highest degree is 3.

12. The degree of equation x² – 9 = 2x² is:

A. 0
B. 1
C. 2
D. 3

Answer: C. 2
Explanation: Degree is the highest power of the variable in an equation. Therefore, in the given equation, the highest degree is 2.

13. What is the value of x if x + 9 = 12?

A. 2
B. 3
C. 8
D. 6

Answer: B. 3
Explanation: x + 9 = 12
X = 12 – 9
X = 3

14. If a number is divided by 8 it gives 6 as the value. Find the number.

A. 36
B. 42
C. 48
D. 56

Answer: C. 48
Explanation: Let X be the number
X/8 = 6
X = 8 x 6 = 48

15. Solve 2x + 9 = 4.

A. X = 6
B. X = -5/2
C. X = -3/2
D. X = -9/2

Answer: B. X = -5/2

2x + 9 = 4
2x = 4 – 9
2x = -5
x = -5/2

16. Find the value of x if 2x + 10 = 76.

A. 33
B. 7.6
C. 66
D. 32

Answer: A. 33
Explanation: 2x + 10 = 76
2x = 76 – 10
2x = 66
x = 66/2
x = 33

17. The perimeter of a rectangle is 40 cm. If its width is 10 cm, then find the length.

A. 10
B. 20
C. 30
D. 40

Answer: A. 10

Explanation: Perimeter of a rectangle = 40 cm
Width = 10 cm
Let the length be x.
Perimeter of rectangle = 2(length + width)
40 = 2 (x + 10)
40/2 = x + 10
20 = x + 10
x = 20 – 10 = 10
Thus, the length is also 10 cm.
Hence, we can say, that the given rectangle is basically a square, with all its sides equal.

18. If x is an even number, then the next even number is:

A. x+1
B. x+2
C. x+3
D. x+4

Answer: B. x+2
Explanation: If x = 2, then x + 2 = 2 + 2 = 4

19. The difference between the two numbers is 30. If the bigger number is x, then what is the smaller number?

A. x – 30
B. 30 – x
C. 30x
D. None of these

Answer: A. x – 30
Explanation: x – small number = 30
Small number = x – 30

20. When a number is added to itself, it becomes 24. What is the number?

A. 2
B. 4
C. 12
D. 21

Answer: C. 12
Explanation: Let the number be x.
x + x = 24
2x = 24
x = 24/2
x = 12