Class 8 Mathematics MCQ Linear Equations In One Variable

Question : The root of the equation z + 4 = -8 is
(a) 3
(b) -32
(c) 12
(d) 4.

Question : If x is an even number then the consecutive even number is
(a) x + 1
(b) x + 2
(c) 2x
(d) x – 1.

Question :Amina thinks of a number and subtracts $\frac { 5 }{ 2 }$ from it. She multiplies the result by 8. The result now obtained is 3 times the same number she thought of. What is the number?
(a) 2
(b) 3
(c) 4
(d) none of these

Question :Solve 2x − 3 = x + 2
(a) 4
(b) 5
(c) 3
(d) 0

Question :Find the solution of 2x – 3 = 7
(a) 3
(b) 4
(c) 5
(d) none of these

Question :David cuts a bread into two equal pieces and cuts one half into smaller pieces of equal size. Each of the small pieces is twenty grams in weight. If he has seven pieces of the bread all with him, how heavy is the original cake.
(a) 120 gm
(b) 180 gm
(c) 300 gm
(d) 240 gm

Question :What will be the solution of these equations ax+by = a-b, bx-ay = a+b
(a) x = 1, y = 2
(b) x = 2,y = -1
(c) x = -2, y = -2
(d) x = 1, y = -1

Question :Solve: y + 3 = 10
(a) 13
(b) 7
(c) -7
(d) none of these

Question :Aruna cut a cake into two halves and cuts one half into smaller pieces of equal size. Each of the small pieces is twenty grams in weight. If she has seven pieces of the cake in all with her, how heavy was the original cake ?
(a) 120 gm
(b) 180 gm
(c) 300 gm
(d) 240 gm

Question :An MNC company employed 25 men to do the official work in 32 days. After 16 days, it employed 5 more men and work was finished one day earlier. If it had not employed additional men, it would have been behind by how many days?
(a) 1 day
(b) 2 days
(c) 3 days
(d) 2.5 days

Question :Solve 2y + 9 = 4.
(a) $\frac { -5 }{ 2 }$
(b) $\frac { 1 }{ 2 }$
(c) 2
(d) none of these

Question :In an equation the values of the expressions on the LHS and RHS are _______.
(a) different
(b) not equal
(c) equal
(d) none of these

Question :The distance between two mile stones is 230 km and two cars start simultaneously from the milestones in opposite directions and the distance between them after three hours is 20 km. If the speed of one car is less than that of other by 10 km/h, find the speed of each car.
(a) 25 km/h, 40 km/h
(b) 40 km/h, 50 km/h
(c) 20 km/h, 40 km/h
(d) 30 km/h, 40 km/h

Question :The sum of three consecutive multiples of 7 is 357. Find the smallest multiple.
(a) 112
(b) 126
(c) 119
(d) 116

Question :In the following number sequence, how many such even numbers are there which are exactly divisible by its immediate preceding number but not exactly divisible by its immediate following number?
3 8 4 1 5 7 2 8 3 4 8 9 3 9 4 2 1 5 8 2
(a) One
(b) Two
(c) Three
(d) Four

Question :The numerator of a fraction is 4 less than the denominator. If the numerator is decreased by 2 and denominator is increased by 1, then the denominator is eight times the numerator. Find the fraction.
(a) $\frac { 4 }{ 12 }$
(b) $\frac { 3 }{ 13 }$
(c) $\frac { 3 }{ 7 }$
(d) $\frac { 11 }{ 7 }$

Question :Mary was counting down from 34 and Thomas was counting upwards simultaneously, the number starting from 1 and he was calling out only the odd numbers. Which common number will they call out at the same time if they were calling out at the same speed?
(a) 20
(b) 21
(c) 22
(d) 23

Question : 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

Question : The solution of 2x-3=7 is:
(a) 5
(b) 7
(c) 12
(d) 11

Question : The solution of 2y + 9 = 4 is:
(a) 9/2
(b) 4/9
(c) -⅖
(d) -5/2

Question : The solution of y/5 = 10 is:
(a) 15
(b) 10
(c) 50
(d) 5

Question : What should be added to -7/3 to get 3/7?
(a) 21/58
(b) 58/21
(c) 47/21
(d) 50/21

Question : 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

Question : 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

Question : 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

Question : 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

Question : The solution for 3m = 5m – (8/5) is:
(a) 8/5
(b) ⅘
(c) 5/4
(d) 4/3

Question : The degree of x² – 5x + 2 = x³ is:
(a) 3
(b) 2
(c) 1
(d) 0

Question : The degree of equation x² – 9 = 2x² is:
(a) 0
(b) 1
(c) 2
(d) 3

Question : What is the value of x if x + 9 = 12?
(a) 2
(b) 3
(c) 8
(d) 6

Question : If a number is divided by 8 it gives 6 as the value. Find the number.
(a) 36
(b) 42
(c) 48
(d) 56

Question : Solve 2x + 9 = 4.
(a) X = 6
(b) X = -5/2
(c) X = -3/2
(d) X = -9/2

Question : Find the value of x if 2x + 10 = 76.
(a) 33
(b) 7.6
(c) 66
(d) 32

Question : 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

Question : If x is an even number, then the next even number is:
(a) x+1
(b) x+2
(c) x+3
(d) x+4

Question : 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

Question : When a number is added to itself, it becomes 24. What is the number?
(a) 2
(b) 4
(c) 12
(d) 21