MCQ Questions for Class 6 Maths Playing With Numbers Quiz 2

The resultant of "factor

$\times$ factor

$......$ " is equal to

0%
product
0%
difference
0%
sum
0%
quotient

Explanation

Let us consider two factors as

$2$ and

$3$

Then

$2\times 3=6$

So, factor

$\times$ factor

$=$ Product

21 and 29 are ______ numbers.

0%
prime numbers
0%
co-primes
0%
multiples of 7
0%
even numbers

Explanation

A set of numbers which do not have any other common factor other than

$1$ are called co-prime.

$21$ &

$29$ have no common factors except

$1$ .

So, they are co-prime numbers.

Hence, option B is correct.

Number of prime numbers from 1 to 50 are

0%
$18$
0%
$12$
0%
$15$
0%
$20$

Explanation

There are 15 prime numbers from 1 to 50. They are

$2, 3, 5, 7, 11, 13, 17,19, 23, 29, 31,37,41,43,47.$

All prime numbers are

0%
even numbers
0%
odd numbers
0%
composite numbers
0%
odd numbers except 2

Explanation

Prime numbers are

$2,3,5,7,11,13,....$

Only

$2$ is an even number and others are odd numbers.

So, all prime numbers are odd numbers except for

$2$ .

Hence, correct answer is option D.

Which of the following numbers are divisible by 2 but not by 4?

0%
28
0%
324
0%
2356
0%
8026

Explanation

$\Rightarrow$ Divisibility by 2: Any even number or number whose last digit is an even number i.e. 2,4,6,8 including 0 is always completely divisible by 2.

$\Rightarrow$ Divisibility by 4: If the last two digits of a number are divisible by 4, then that number is a multiple of 4 and is divisible by 4 completely.

$\Rightarrow$

$28,\,324$ and

$2356$ are divisible by both 2 and 4.

$\Rightarrow$

$8026$ contains last digit 6, so it is divisible by 2.

$\Rightarrow$

$8026$ last two digit is not divisible by 4.

$\therefore$

$8026$ is the number which is divisible by 2 but not 4.

A number which is a factor of every number is

0%
$0$
0%
$1$
0%
$2$
0%
none of these

Explanation

${\textbf{Step - 1: Solve with example}}$

${\text{As we know Factors are all the numbers that divide a number completely, }}$

${\text{i}}{\text{.e}}{\text{., without leaving any remainder, are called factors of that number}}{\text{.}}$

${\text{Multiples are those numbers which on multiplication give the desired number}}{\text{. }}$

${\text{All these multiples individually can be named as a factor of the given number}}{\text{.}}$

${\textbf{Step -2: Find factors}}$

${\text{To find the factors of any given number, }}$

${\text{we express each number as a product of prime numbers since they do not leave any remainder}}{\text{.}}$

${\text{For example, consider some numbers such as 1, 8, 21, 29}}{\text{.The factor of 1 is 1}}{\text{.}}$

${\text{The factors of 8 are 1, 2, 4 and 8}}{\text{.}}$

${\text{The factors of 21 are 1, 3, 7 and 21}}$

${\text{The factors of 29 are 1 and 29}}{\text{.}}$

${\text{From the above data, we observe that - }}$

${\text{1 is the greatest factor of itself and the smallest factor of any other number}}{\text{.}}$

${\textbf{Hence, the correct answer is option B}}{\text{. }}$

HCF of

$24$ and

$36$ is ..............

0%
$6$
0%
$4$
0%
$9$
0%
$12$

Explanation

$2\underline {|24} {\;} 2\underline {|36}$

$2\underline {|12} {\;} 2\underline {|18}$

$2\underline {|6} {\;} 3\underline {|9}$

$3\underline {|3} {\;} 3\underline {|3}$
1 1

$24 = 2 \times 2 \times 2 \times 3$

$36 = 2 \times 2 \times 3 \times 3$

$\therefore H.C.F=2\times 2 \times 3=12$

The prime number that comes just after 47 is ......

0%
57
0%
51
0%
53
0%
none of these

Explanation

After

$47$ ,

$48,49,50,51,52$ are composite numbers; but,

$53$ is a prime number, as it has no factor other than 1 and itself.

So correct answer will be option C

Choose the co-prime numbers from the following pairs:

0%
$(11, 111)$
0%
$(22, 222)$
0%
$(12,36)$
0%
$(14,50)$

Explanation

A set of numbers that do not have any other common factor other than

$1$ are called co-prime.

$11$ ,

$111$ are co-prime numbers because they do not have any proper common factor other than 1

$11 = 1 \times 11$

$111 = 1 \times 111$

Which prime number which comes just after

$43$ ?

0%
$49$
0%
$45$
0%
$47$
0%
none of these

Explanation

Numbers after

$43$ are

$43, 44, 45, 46, 47, 48...$

$44$ is a composite number as it has more than two factors

$1, 2, 11, 22, 44$
Similarly,

$45, 46$ has more than two factors.

However

$47$ has only two factors

$1, 47$ .
Thus the next prime number after

$43$ is

$47.$

Number of prime numbers between

$50$ to

$60$ is

0%
$1$
0%
$2$
0%
$3$
0%
$4$

Every prime number is

$.......$

0%
a even number
0%
an odd number
0%
a composite number
0%
none of these

Explanation

Prime numbers have only two factors

$1$ and the number itself.

For example,

$2, 3, 5, 7, 11..$

From this, we notice that all prime numbers cannot be put to one category except being non-composite.

A prime number

0%
has exactly one factor.
0%
has exactly two factors.
0%
is not divisible by $2$ .
0%
is an odd number.

Explanation

A prime number has only two factors.

For eg.

$11, 17$ , etc..

Each of these numbers is divisible by

$1$ and itself.

Hence, option B is correct.

Which of the following are prime numbers?

0%
$137$
0%
$143$
0%
$396$
0%
Both A and B

Explanation

$143=11\times 13$

$396=2\times198$

Only

$137$ is a prime number.

The numbers which are multiples of 2 are called

0%
odd
0%
prime
0%
composite
0%
none of these

Explanation

The numbers which are multiples of 2 are called even number.
Ex-

$2,4,6,8,10$ etc.

All these numbers are divisible by

$2$ .

Number of prime numbers between

$50$ to

$60$ is

0%
$1$
0%
$2$
0%
$3$
0%
$4$

Explanation

The prime numbers between

$50$ and

$60$ are

$53$ and

$59.$
Hence, number of prime numbers between

$50$ and

$60$ is

$2.$

Which is the least prime number ?

0%
$1$
0%
$0$
0%
$2$
0%
$3$

Explanation

The prime numbers are

$2,3,5.......$

So least prime is

$2.$

HCF of two co-prime numbers is

0%
$1$
0%
$0$
0%
$2$
0%
None of these

Explanation

${\textbf{Step - 1: Find the required answer using definition of co-prime numbers.}}$

${\text{By definition of co-prime numbers,}}$

${\text{Two numbers having only 1 as their common factor are called co-prime numbers.}}$

${\text{So, HCF of two co-prime numbers is 1.}}$

${\textbf{Hence, the correct option is A.}}$

If the HCF of two numbers is 1, then they are called as ?

0%
Co-primes
0%
Composite numbers
0%
Prime numbers
0%
Twin primes

Explanation

If the HCF of two numbers is

$1$ , then they are called as coprime numbers. eg..

$4$ and

$15$ .

Identify prime numbers among the following options.

0%
$2$
0%
$5$
0%
$6$
0%
$8$

Explanation

$2$ has two factors only, namely

$2$ and

$1.$

$5$ has two factors only, namely

$5$ and

$1.$

So, options

$A$ and

$B$ are correct.

Choose the co-prime numbers from the following pairs

0%
$7\ and \ 63$
0%
$39 \ and \ 25$
0%
$35\ and\ 21$
0%
63 and 81

Explanation

A set of numbers which do not have any other proper common factor other than

$1$ are called co-prime.

Given numbers are

$39 \ and \ 25$

$39=3\times 13$

$25=5\times5$

HCF

$=1$

The number which is neither prime nor composite is

0%
$0$
0%
$1$
0%
$2$
0%
$5$

Explanation

$1$ is the number which is neither prime nor composite.
Because

$1$ has only

$1$ divisor which is

$1$ only.

If a number is divisible by 9, then it is also divisible by which number?

0%
3
0%
6
0%
2
0%
None of these

Explanation

If a number is divisible by

$9$ , then it is also divisible by

$3$ as

$9 = 3 \times 3$

Which of the following numbers are not divisible by

$5$ ?

$30,49,75,210,305$

0%
$30$
0%
$49$
0%
$75$
0%
$210$

Explanation

Given list of numbers are

$30, 49, 75, 210, 305$
Numbers ending in either

$5$ or

$0$ are divisible by

$5$ .

Hence,

$49$ is not divisible by

$5$ .

Which of the following numbers are not divisible by

$3$ ?

$42,73,84,105,314$

0%
$42$
0%
$73$
0%
$84$
0%
$314$

Explanation

We use a rule to check whether the number is divisible by 3 or not.

A number is divisible by 3 if the sum of the digits is evenly divisible by 3.

$4+2 = 6$ , divisible by 3

$7+3 = 10$ , not divisible by 3
C.

$8+4 = 12$ , divisible by 3
D.

$3+1+4 =8$ , not divisible by 3.

By Goldbach's conjecture, every even number greater than 4 can be expressed as a sum of

0%
Two even numbers
0%
Two odd prime numbers
0%
Two composite numbers
0%
Two co-prime numbers

Explanation

Goldbach's conjecture says that "Every integer greater than

$2$ can be expressed as the sum of

$2$ prime numbers."

How many prime numbers are there between 10 and 30?

0%
$6$
0%
$5$
0%
$7$
0%
$8$

Explanation

${\because}$ The prime numbers between

$10$ and

$30$ are

$11,13,17,19,23,29.$

How many factors does the number

$24$ has ?

0%
$2$ factors
0%
$4$ factors
0%
$6$ factors
0%
$8$ factors

Explanation

Factors of

$24$ are

$1,2,3,4,6,8,12,24$

Which of the following numbers are not divisible by

$2$ ?

$57, 34, 60, 93, 126$

0%
$57$
0%
$34$
0%
$93$
0%
$126$

Explanation

If a number is divisible by

$2$ ,

then the digit in the units place should be either

$0, 2, 4, 6$ or

$8.$

Here,

$57$ &

$93$ ends with 7 and 3 respectively and hence not divisible by 2.

Which of the following numbers are not divisible by

$9$ ?

$36,90,157,243,514$

0%
$36$
0%
$90$
0%
$157$
0%
$243$

Explanation

If the sum of all the digits of a number is divisible by

$9$ then the number is divisible by

$9$ .

$36$

$3+6 = 9 = 9\times 1 ,$ which is multiple of

$9$

$90$

$9+0 = 9 = 9\times 1 ,$ which is multiple of

$9$

$157$

$1+5+7 = 13 ,$ which is not a multiple of

$9$ .

$243$

$2+4+3 = 9 = 9\times 1 ,$ which is multiple of

$9$

Hence, the correct answer is

$Option-(C)$

CBSE Questions for Class 6 Maths Playing With Numbers Quiz 2 - MCQExams.com

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Practice Class 6 Maths Quiz Questions and Answers

CBSE Questions for Class 6 Maths Playing With Numbers Quiz 2 - MCQExams.com

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Practice Class 6 Maths Quiz Questions and Answers

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