Revision Test II

Download CBSE Class 8th Standard CBSE Mathematics question papers, sample papers, important questions, and previous year solved papers in PDF format. Get free study materials, NCERT solutions, and exam preparation resources for Class 8th Standard CBSE Mathematics

Questions:

Multiple Choice Question

10 x 1 = 10

Which of the following is neither positive nor a negative rational number?

(a)

(b)

(c)

Such a rational number does not exist

(d)

None of the above

Which of the following is the multiplicative identity for rational numbers?

(a)

(b)

-1

(c)

(d)

None of these

Which of the following is the identity element?

(a)

(b)

-1

(c)

(d)

None of these

What should be subtracted from \(\frac { -3 }{ 4 } \) to get - 1?

(a)

\(\frac { 1 }{ 4 } \)

(b)

\(-\frac { 1 }{ 4 } \)

(c)

(d)

\(-\frac { 3 }{ 4 } \)

What should be added to \(\frac { -3 }{ 4 } \) to get -1?

(a)

\(\frac { 1 }{ 4 } \)

(b)

\(\frac { -1 }{ 4 } \)

(c)

(d)

\(\frac { -3 }{ 4 } \)

The value of \(\frac{1}{9^{-2}}\) is

(a)

(b)

(c)

-81

(d)

5^-2 can be written as

(a)

\(\frac{1}{5}\)

(b)

\(\frac{1}{5^{2}}\)

(c)

5²

(d)

-\(\frac{2}{5}\)

In 3ⁿ, n is known as

(a)

base

(b)

constant

(c)

exponent

(d)

variable

Which of the following is not true?

(a)

rational numbers are closed under addition

(b)

rational numbers are closed under subtraction.

(c)

rational numbers are closed under multiplication

(d)

rational numbers are closed under division

10.

The numerical expression \({3 \over 8} + {(-5)\over 7}={-19\over 56}\) shows that

(a)

rational numbers are closed under addition

(b)

rational numbers are not closed under addition

(c)

rational numbers are closed under multiplication

(d)

addition of rational numbers is not commutative.

True or False

10 x 1 = 10

11.

Every rhombus is a parallelogram

(a)

True

(b)

False

12.

Every rectangle is a rhombus

(a)

True

(b)

False

13.

Every rhombus is a rectangle.

(a)

True

(b)

False

14.

Every square is a rhombus

(a)

True

(b)

False

15.

Every rhombus is a square

(a)

True

(b)

False

16.

Zero is a rational number

(a)

False

(b)

True

17.

All the fractions are not rational numbers but all the rational numbers are fractions

(a)

True

(b)

False

18.

All the integers are rational numbers.

(a)

False

(b)

True

19.

All the whole numbers are integers

(a)

False

(b)

True

20.

All the natural numbers are whole numbers.

(a)

False

(b)

True

Generic 2

11 x 2 = 22

21.

How many integers are there between - 1and 1?

22.

Is \([(10)\div 2] \div (-5) = (-10) \div [2 \div (-5)] ?\)

23.

\(- \frac{3}{8}+\frac{(-4)}{5}=\frac{-15+(-32)}{40}=\) _______ Is it a rational number?

24.

4 + 7 =_________ Is it a whole number?

25.

Write each of the following in standard form: 150,000,000,000

26.

Can \(\frac { { a }^{ m } }{ b^{ m } } \) be equal to \({ \left( \frac { a }{ b } \right) }^{ m }\)?

27.

What is the standard form of 3600000000000?

28.

What is the reciprocal of 0.1?

29.

The product of two rational numbers is \(\frac { -28 }{ 75 } \) if one of the numbers is \(\frac { 14 }{ 25 } \) find the other

30.

Multiply the reciprocal of \(\frac { 7 }{ 8 } \) by the reciprocal of \(\frac { -2 }{ 21 } \)

31.

Write the rational number for each point labelled with a letter

Generic 5

5 x 5 = 25

32.

Complete the following crossword puzzle using given directions.
Across:
(1) The negative of a rational number is called its ______.
(2) A number of the form where p and q are integers and q \(\neq \) 0, is called a ________.

(3) The________ of a rational number and its product is 1.
(4) The multiplicative inverse of a number is also called its _____.
(5) Zero is also called the________ identity for rational numbers.
(6) If the product of two rational numbers is 1, then they are called multiplicative_______ of each other.
(7) The rational number is________ the additive identity for rational numbers.

33.

Find the area of the following trapezium.

34.

Find three rational numbers between \(\frac { 1 }{ 2 } \) and (-2)

35.

Represent \({8\over3}and-{8\over3}\) on the number line

36.

Find five rational numbers between \(-{1\over2}and{2\over3}\)

Match the following

5 x 1 = 5

37.

(a + b)+ c= a + (b+ c) is called

38.

axb=bxa is called

39.

a+b=b+a is called

40.

a x (bx c) = (a x b)x c is called

41.

a(b+ c) = ab + ac is called

Generic 3

6 x 3 = 18

42.

Find \(\frac{-1}{2}+[\frac{3}{7}+(\frac{-4}{3})]\) and \([\frac{-1}{2}+\frac{3}{7}]+(\frac{-4}{3})\). Are the two sums equal ?

43.

Complete the following crossword puzzle using the given directions for Across [from left to right] and Down [from top to bottom].

Direction:
Across:
(1) The product of a number by itself three times, is called a _________
Down:
(2) Prime factors of a perfect cube can be grouped into complete__________
(3) The reverse process of finding the cube of a number is finding the ___________of that number.
(4) Numbers that are not exactly divisible by 2, are called__________
(5) The factors of a number, that are prime numbers, are called___________ of the number.

44.

By prime factorisation, find the cube roots of 1331

45.

Is 68600 a perfect cube? If not, find the smallest number by which 68600 must be multiplied to get a perfect cube

46.

Simplify: \({ \left[ { \left( \frac { -4 }{ 5 } \right) }^{ -2 } \right] }^{ 2 }\)

47.

Fill in the blanks in the following table:

Number	Closed Under
	Addition	Subtraction	Multuplication	Division
Rational numbers	Yes	Yes	...	No
Integers	...	Yes	...	No
Whole numbers	...	...	Yes	...
Natural numbers	...	No	...	...

Generic 4

2 x 4 = 8

48.

Leela invited some friends for tea on her birthday. Her mother placed some plates and some puris on a table to be served. If Leela places 4 puris in each plate 1 plate would be left empty. But if she places 3 puris in each plate 1puri would be left. Find the number of plates and number of puris on the table.

49.

Take a clock and fix its minute hand at 12.
Record the angle turned through by the minute hand from its original position and the time that has passed, in the following table:

Time Passed (T) (in minutes)	(T₁) 15	(T₂) 15	(T₃) 45	(T₄) 60
Angle turned (A) (in degree)	(A₁) 90	(A₂) __	(A₃) __	(A₄) __
\(T\over A\)	-	-	-	-

What do you observe about T and A? Do they increase together? Is \(T\over A\) same every time?

Is the angle turned through by the minute hand directly proportional to the time that has passed? Yes; From the above table, you can also see
T₁ : T₂ = A₁ A₂, because
T₁ : T₂ = 15 30= 1 :2
A₁ : A₂ = 90 180 = 1 :2
Check if T₂: T₃ = A₂ A₃ and T₃ : T₄ = A₃ : A₄
You can repeat this activity by choosing your own time interval.

Visit QB365-SLMS - https://www.qb365.in/slms/

Answers Key:

Multiple Choice Question

10 x 1 = 10

(b)
0

(a)
1

(a)
\(\frac { 1 }{ 4 } \)

(b)
\(\frac { -1 }{ 4 } \)

(b)
81

(b)
\(\frac{1}{5^{2}}\)

(d)
rational numbers are closed under division

10.

(a)
rational numbers are closed under addition

True or False

10 x 1 = 10

11.

(a)
True

12.

(b)
False

13.

(b)
False

14.

(a)
True

15.

(b)
False

16.

(a)
False

17.

(b)
False

18.

(a)
False

19.

(a)
False

20.

(a)
False

Generic 2

11 x 2 = 22

21.

There is only one integer between - 1 and 1. It is 0.

22.

\([(10)\div 2] \div (-5) = (-5) \div (-5) = 1\)
\( (-10) \div [2 \div (-5)] =(-10) \div (- \frac{2}{5})\) = 25
∵ 1 ≠ 25
∴ No ; \([(10)\div 2] \div (-5) \ne (-10) \div [2 \div (-5)].\)

23.

\(- \frac{3}{8}+\frac{(-4)}{5}=\frac{-15+(-32)}{40}=\frac{-47}{40}\)
Yes; it is a rational number.

24.

4 + 7 = 11;
Yes; it is a whole number.

25.

1.5 \(\times\) 10¹¹

26.

Yes

27.

3.6 \(\times\) 10¹²

28.

29.

\(\therefore\) product of two rational numbers = \(\frac { -28 }{ 75 } \)
Any one of the ratioanl numbers = \(\frac { 14 }{ 25 } \)
\(\therefore\) the other number = \(\left[ \frac { -28 }{ 75 } \right] \div \frac { 14 }{ 25 } \)
= \(\frac { -28 }{ 75 } \times \frac { 25 }{ 14 } =\frac { -2\times 1 }{ 3\times 1 } =\frac { -2 }{ 3 } \)
Thus, the required rational number is \(\left( \frac { -2 }{ 3 } \right) \)

30.

\(\therefore\) Reciprocal of \(\frac { 7 }{ 8 } \) is \(\frac { 8 }{ 7 } \)
Reciprocal of \(\frac { -2 }{ 21 } \) is \(\frac { -21 }{ 2 } \)
\(\therefore\) \(\left[ Reciprocal\ of\frac { 7 }{ 8 } \right] \times \left[ Reciprocal\ of\left( \frac { -2 }{ 21 } \right) \right] \)
= \(\frac { 8 }{ 7 } \times \left( \frac { -21 }{ 2 } \right) =\frac { 4\times (-3) }{ 1\times 1 } =-12\)

31.

\(A={\frac{-15}{8}},B={-14\over8},c={-11\over8},D={-8\over8}E={-7\over8}\)

Generic 5

5 x 5 = 25

32.

(1) \(\rightarrow\) Additive Inverse
(2) \(\rightarrow\) Rational Inverse
(3) \(\rightarrow\) Product
(4) \(\rightarrow\) Reciprocal
(5) \(\rightarrow\) Additive
(6) \(\rightarrow\) Inverse
(7) \(\rightarrow\) Zero

33.

Here, parallel sides are 25 cm and 15 cm.
Height (i.e. distance between the parallel sides) = 12 cm
\(\because\) Area of a trapezium ABCD
\(=\frac{1}{2}\times(Sum\ of\ parallel\ sides)\times \ Height\)
\(\therefore\) Area of the trapezium ABCD
\(=\frac{1}{2}\times(25\ cm+15\ cm)\times12\ cm\)
\(=\frac{1}{2}\times40\times12\ cm^2=240\ cm^2\)
Thus, the required area of the trapezium ABCD = 240 cm².

34.

We have
A rational number between \(\frac { 1 }{ 2 } \)
= \(\left[ \frac { 1 }{ 2 } +(-2) \right] \div 2=\left[ \frac { 1-4 }{ 2 } \right] \div 2\)
= \(\left[ \frac { -3 }{ 2 } \right] \times \frac { 1 }{ 2 } =\frac { -3 }{ 4 } \)
A rational number between \(\frac { 1 }{ 2 } \) and \(\left( \frac { -3 }{ 4 } \right) \)
= \(\left[ \frac { 1 }{ 2 } +\left( \frac { -3 }{ 4 } \right) \right] \div 2\)
\(\left[ \frac { 2-3 }{ 4 } \right] \times \frac { 1 }{ 2 } =\frac { -1 }{ 4 } \times \frac { 1 }{ 2 } =\frac { -1 }{ 8 } \)
A rational number between \(\left( \frac { -3 }{ 4 } \right) \) and (-2)
= \(\left[ \left( \frac { -3 }{ 4 } \right) +(-2) \right] \div 2=\left[ \frac { (-3)+(-8) }{ 4 } \right] \times \frac { 1 }{ 2 } \)
= \(\frac { -11 }{ 4 } \times \frac { 1 }{ 2 } =\frac { -11 }{ 8 } \)
Thus, the three rational numbers
\(\left( \frac { -3 }{ 4 } \right) ,\left( \frac { -1 }{ 8 } \right) \) and \(\left( \frac { -11 }{ 8 } \right) \) are between \(\frac { 1 }{ 2 } \) and (-2)

35.

36.

\(-{2\over6},-{1\over6},0,{1\over6},{2\over6}\)

Match the following

5 x 1 = 5

37.

()
Commutative property for addition

38.

()
Commutative property for multiplication

39.

()
Commutative property for addition

40.

()
Associative property for multiplication

41.

()
Distributive property for addition

Generic 3

6 x 3 = 18

42.

\(\frac{-1}{2}+[\frac{3}{7}+(\frac{-4}{3})] = \frac{-1}{2}+(\frac{-19}{21})=\frac{-59}{42}\)
\([\frac{-1}{2}+\frac{3}{7}]+(\frac{-4}{3})=\frac{-1}{14}+(\frac{-4}{3})=\frac{-59}{42}\)
So, Yes ; \(\frac{-1}{2}+[\frac{3}{7}+(\frac{-4}{3})]=[\frac{-1}{2}+\frac{3}{7}]+(\frac{-4}{3})\)
i.e., the two sums are equal.

43.

(1)PERFECT-CUBE
(2)TRIPLES
(3)CUBE-ROOT
(4)ODD NUMBER
(5)PRIME-FACTORS

44.

45.

46.

Since, \({ \left( \frac { a }{ b } \right) }^{ m }=\frac { { a }^{ m } }{ { b }^{ m } } \quad and\quad { (a }^{ m })^{ n }={ a }^{ mn }\)
\(\therefore \quad { \left[ { \left( \frac { -4 }{ 5 } \right) }^{ -2 } \right] }^{ 2 }={ \left( \frac { -4 }{ 5 } \right) }^{ -2\times 2 }={ \left( \frac { -4 }{ 5 } \right) }^{ -4 }={ \left( \frac { 5 }{ -4 } \right) }^{ 4 }\)
\(=\frac { 5\times 5\times 5\times 5 }{ (-4)\times (-4)\times (-4)\times (-4) } =\frac { 625 }{ 256 } \)
Thuss, \({ \left[ { \left( \frac { -4 }{ 5 } \right) }^{ -2 } \right] }^{ 2 }=\frac { 625 }{ 256 } \)

47.

Using the closure property over addition, subtraction, multiplication and division for rational numbers, integers, whole-numbers and natural numbers, we have:

Number	Closed Under
	Addition	Subtraction	Multuplication	Division
Rational numbers	Yes	Yes	Yes.	No
Integers	Yes	Yes	Yes	No
Whole numbers	Yes	Yes	Yes	No
Natural numbers	Yes	No	Yes	No

Generic 4

2 x 4 = 8

48.

Let the number of plates on the table be y and the number of puris be x.
Then, according to the first condition of the problem
4(y - 1) = x ...(1)
and, according to the second condition of the
problem
3y + 1= x ... (2)
From (1) and (2), we have
4(y - 1) = 3y + 1
⇒ 4y - 4 = 3y + 1
⇒ 4y - 3y = 1 + 4
⇒ y=5
Put y = 5 in (1), we get
x = 4(5) - 4 = 20 - 4 = 16
Hence, the number of plates and number of puris on the table are 5 and 16 respectively.

49.

Time Passed (T) (in minutes)	(T₁) 15	(T₂) 15	(T₃) 45	(T₄) 60
Angle turned (A) (in degree)	(A₁) 90	(A₂) __	(A₃) __	(A₄) __
\(T\over A\)	\({15\over 90}={1\over6}\)	\({30\over 180}={1\over6}\)	\({45\over 270}={1\over6}\)	\({60\over 360}={1\over6}\)

We observe about T and A that they increase together and is \(T\over A\) same every time.
Yes; The angle turned by the minute hand is directly proportional to the time that has passed.
On checking, we find that
T₂ : T₃ = A₁ : A₃ = 2: 3
and T₃ : T₄ = A₃ : A₄ = 3 : 4

Class 8 CBSE Mathematics Revision Test Question Paper

QB365 Student Learing Managemnet System

Std: 8th Standard CBSE - Mathematics

chapter: - Model Question paper

Visit QB365-SLMS - https://www.qb365.in/slms/ Complete Questions and Answers

Questions:

Visit QB365-SLMS - https://www.qb365.in/slms/

Answers Key:

NEW MCQ Practice Test - CBSE Class 8

Mathematics CBSE Class 8 MCQ Practice Test

CBSE Class 8 MCQ Practice Test

8th Standard CBSE Study Materials