MCQ 11 Mark
The successor of the smallest prime number is:
AnswerThe smallest prime number is $2$
So, Successor of $2 = 2 + 1 = 3$
View full question & answer→MCQ 21 Mark
The value of $1735 \times 1232 - 1735 \times 232$ is:
- A
$17350$
- B
$173500$
- ✓
$1735000$
- D
$173505$
AnswerCorrect option: C. $1735000$
Using distributive law of multiplication over subtraction, we get
$1735 \times 1232 - 1735 \times 232 $
$= 1735 (1232 - 232)$
$= 1735 \times 1000$
$= 1735000$
Hence, the correct option is $(c).$
View full question & answer→MCQ 31 Mark
$a$ and $b$ are two co$-$primes. Which of the following is$/$ are true?
AnswerCorrect option: C. Both $(a)$ and $(b).$
A set of numbers which do not have any other common factor other than $1$ are called co$-$prime.
The $\ce{LCM}$ of two co$-$prime numbers is equal to their product.
The $\ce{HCF}$ of two co$-$prime numbers is $1.$
View full question & answer→MCQ 41 Mark
Which one of the following is the smallest even whole number?
AnswerThe natural numbers along with $0$ form the collection of whole numbers.
So, the numbers $0, 1, 2, 3, 4, …$ form the collection of whole numbers.
The number which is divisible by $2$ is an even number.
So, in the collection $“0, 1, 2, 3, 4, …”, 2$ is the smallest even number.
Hence, the correct option is $(c).$
View full question & answer→MCQ 51 Mark
The smallest number which is neither prime nor composite is:
MCQ 61 Mark
Mark the correct alternative in the following: Additive inverse of $28$ is:
- A
$\frac{1}{28}$
- B
$0$
- ✓
$-28$
- D
$82$
AnswerHere, the given number is $28.$
Additive inverse of a given number is a number which when added to the given number gives zero.
Now $28 + (-28) = 0$
Thus, $-28$ is the additive inverse of $28.$
Hence, the correct option is $(c).$
View full question & answer→MCQ 71 Mark
Which one of the following is the smallest odd whole number?
AnswerThe natural numbers along with $0$ form the collection of whole numbers.
So, the numbers $0, 1, 2, 3, 4, …$ form the collection of whole numbers.
A natural number which is not divisible by $2$ is called an odd whole number.
So, in the collection $“0, 1, 2, 3, 4, …”, 1$ is the smallest odd whole number.
Hence, the correct option is $(b).$
View full question & answer→MCQ 81 Mark
Which one of the following whole numbers does not have a predecessor?
AnswerThe numbers $0, 1, 2, 3, 4, ….$ form the collection of whole numbers.
The smallest whole number is $0.$
So, $0$ does not have a predecessor.
Hence, the correct option is $(b).$
View full question & answer→MCQ 91 Mark
The least number divisible by each of the numbers $15, 20, 24$ and $32$ is:
- A
$ 960$
- ✓
$480$
- C
$360$
- D
$640$
Answer$\text{LCM}$ of $15,20,24$ and $32$ is given by $15=3 \times 5=3^1 \times 5^1$
$20=2 \times 2 \times 5=2^2 \times 5^1$
$24=2 \times 2 \times 2 \times 3=2^3 \times 3^1$
$32=2 \times 2 \times 2 \times 2 \times 2=2^5$
$\text{LCM} =2^5 \times 3^1 \times 5^1=480$
View full question & answer→MCQ 101 Mark
The number of whole numbers between the smallest whole number and the greatest $2$ digit number is:
AnswerSmallest whole number $= 0$
Greatest $2-$digit whole number $= 99$
The whole numbers between $0$ and $99$ are $1, 2, 3, 4 …… 97, 98.$
To find the number of whole numbers between $0$ and $99,$
Subtract $1$ from the difference of $0$ and $99.$
Therefore, Number of whole numbers between $0$ and $99 = (99 - 0) - 1$
$= 99 - 1$
$= 98$
Hence, the correct option is $(d).$
View full question & answer→MCQ 111 Mark
The predecessor of $1$ million is:
- A
$9999$
- B
$99999$
- ✓
$999999$
- D
$1000001$
AnswerCorrect option: C. $999999$
We have:
$1$ million $= 10,00,000$
Predecessor of $1$ million,
$= 10,00,000 - 1 $
$= 9,99,999$
View full question & answer→MCQ 121 Mark
If $n$ is a whole number such that $n + n = n, $ then $n =?$
AnswerHere $, 0 + 0 = 0, 1 + 1 $
$= 2, 2 + 2 = 4 …..$
So, the statement $n + n = n $ is true only when $n = 0.$
Hence, the correct option is $(d).$
View full question & answer→MCQ 131 Mark
Mark the correct alternative in the following : What is the additive identity element in the set of whole numbers?
AnswerAn additive identity is a number which when added to any number, the number is unchanged.
For example : $0 + 7 = 7, 0 + 9 $
$= 9, 0 + (- 11) = -11$ etc.
Thus, 0 is the additive identity in the set of whole numbers.
Hence, the correct option is $(a)$.
View full question & answer→MCQ 141 Mark
Mark the correct alternative in the following : $x + 12 = 12 + 7,$ then by commutativity of addition $x =$
AnswerHere $, x + 12 = 12 + 7.$
But, by commutative of addition,
We have $7 + 12 = 12 + 7$
So, comparing $x + 12 = 12 + 7$ and $7 + 12 = 12 + 7$
We have $x = 7$
Hence, the correct option is $(b).$
View full question & answer→MCQ 151 Mark
Mark the correct alternative in the following : Which one of the following is not a natural numbers?
AnswerThe numbers $1, 2, 3, 4, 5, ...$ form the collection of natural numbers.
Thus, $0$ is not a natural number.
Hence, the correct option is $(c)$.
View full question & answer→MCQ 161 Mark
The least number of $4$ digits which is exactly divisible by $9$ is:
- ✓
$1008$
- B
$1009$
- C
$1026$
- D
$1018$
AnswerCorrect option: A. $1008$
Least $4-$ digit number $= 1000$
The least $4-$ digit number exactly divisible by $9$ is $1000 + (9 - 1) = 1008.$
Hence, the correct option is $(a).$
View full question & answer→MCQ 171 Mark
The greatest number which divides $134$ and $167$ leaving $2$ as remainder in each case is:
AnswerFirst we subtract the required remainder from $134$ and $167.$
Thus, we will get $132$ and $165.$
$132 = 2 \times 2 \times 3 \times 11 = 2^2 \times 3 \times 11$
$165 = 3 \times 5 \times 11 = 3^1 \times 5 \times 11$
$\ce{HCF} = 3 \times 11 = 33$
Thus, the greatest number which divides $134$ and $167$ leaving $2$ as remainder in each case is $33$
View full question & answer→MCQ 181 Mark
Mark the correct alternative in the following: If n is an odd natural number greater than $1,$ then the product of its successor and predecessor:
- A
Is an odd natural number.
- ✓
Is an even natural number.
- C
- D
AnswerCorrect option: B. Is an even natural number.
Is an even natural number.
View full question & answer→MCQ 191 Mark
The successor of $1$ million is:
- A
$10,001$
- B
$1,00,001$
- ✓
$10,00,001$
- D
$1,00,00,001$
AnswerCorrect option: C. $10,00,001$
We have:
$1$ million $= 10,00,000$
Predecessor of $1$ million,
$= 10,00,000 + 1 = 10,00,001$
View full question & answer→MCQ 201 Mark
The predecessor of the smallest $3$ digit number is:
AnswerSmallest $3-$ digit number $= 100$
Predecessor of $3-$ digit number,
$= 100 - 1 = 99$
Hence, the correct option is $(b)$.
View full question & answer→MCQ 211 Mark
The smallest natural number is :
MCQ 221 Mark
Which one of the following is the smallest whole number?
AnswerThe set of whole numbers is $\{0, 1, 2, 3, 4, …\}$
So, the smallest whole number is $0$
Hence, the correct option is $(c)$.
View full question & answer→MCQ 231 Mark
If $x$ and $y$ are co $-$ primes, then their $\text{LCM}$ is:
AnswerA set of numbers which do not have any other common factor other than $1$ are called co $-$ prime.
The $\text{LCM}$ of two co $-$ prime numbers is equal to their product.
View full question & answer→MCQ 241 Mark
Mark the correct alternative in the following: What is the multiplicative identity element in the set of whole numbers?
AnswerA multiplicative identity is a number which when multiplied with any number, the number is unchanged.
For example: $1 \times 7 = 7, 1 \times 9 = 9, 1 \times 100 = 100$ etc.
Thus, $1$ is multiplicative identity in the set of whole numbers is $1.$
Hence, the correct option is $(c).$
View full question & answer→MCQ 251 Mark
The value of $47 \times 99$ is:
- A
$4635$
- ✓
$4653$
- C
$4563$
- D
$6453$
AnswerCorrect option: B. $4653$
Since, $99 = 100 - 1$
Therefore, $47 \times 99 = 47 \times (100 - 1)$
$= 47 \times 100 - 47$
$= 4700 - 47$
$= 4653$
Thus, the value of $47 \times 99$ is $4653$.
Hence, the correct option is $(b).$
View full question & answer→MCQ 261 Mark
Mark the correct alternative in the following: If $n$ is an even number, then the product of its successor and predecessor
- A
Is an even natural number.
- ✓
Is an odd natural number.
- C
- D
AnswerCorrect option: B. Is an odd natural number.
Here $,n$ is an even number.
Successor of $n = n + 1$
Predecessor of $n = n − 1$
Product $= (n + 1) \times (n − 1) =$ odd $\times$ odd $=$ odd
Thus, the product of the successor and the predecessor of $n$ is an odd natural number.
Hence, the correct option is $(b)$.
View full question & answer→MCQ 271 Mark
Mark the correct alternative in the following: Which of the following is not zero?
- A
$0\times0$
- B
$\frac{0}{2}$
- C
$\frac{(6-6)}{2}$
- ✓
$4+0$
AnswerIn the product of two numbers, if one of the numbers $($or both$)$ is $($are$)$ zero, then the product is zero.
$\therefore0\times0=0$
In a division, if the numerator is zero, then the answer is zero.
$\therefore\frac{0}{2}=0$
Similarly, $\frac{(6-6)}{2}=\frac{0}{2}=0$
Here, $0$ is an additive identity in the set of whole numbers.
$\therefore4 + 0 =4$
Thus $, 4 + 0$ is not zero.
Hence, the correct option is $(d)$.
View full question & answer→MCQ 281 Mark
Mark the correct alternative in the following: If $(31 + 15) + x = 31 + (15 + 23),$ then by associativity of addition $x =?$
AnswerHere, $(31 + 15) + x = 31 + (15 + 23).$
But, by associativity of addition,
We have $(31 + 15) + 23 = 31 + (15 + 23)$
So, comparing $(31 + 15) + x = 31 + (15 + 23) $ and $(31 + 15) + 23 = 31 + (15 + 23),$
We have $x = 23$
Hence, the correct option is $(c).$
View full question & answer→MCQ 291 Mark
The $\ce{HCF}$ of two co$-$primes is:
AnswerA set of numbers which do not have any other common factor other than $1$ are called co$-$prime.
View full question & answer→MCQ 301 Mark
The product of a whole number $($other than zero$)$ and its successor is:
- ✓
- B
- C
Divisible by $4$
- D
Divisible by $3$
AnswerWe have:
Whole number $= 1$
Successor of $1 = 1 + 1 = 2$
Their product $= 1 \times 2 = 2$
Thus, $2$ is an even number.
View full question & answer→MCQ 311 Mark
The $\ce{HCF}$ of two co$-$primes is:
AnswerThe smallest prime number is $2.$
Thus, when we multiply any natural number we will always get an even number.
View full question & answer→MCQ 321 Mark
How many whole numbers are between $437$ and $487?$
AnswerThe whole numbers between $437$ and $487$ are $438, 439, 440, 441, … , 484, 485$ and $486.$ To find the required number of whole numbers,
We need to subtract $437$ from $487$ and then subtract again $1$ from the result.
Thus, there are $(487 - 437) - 1$ whole numbers between $437$ and $487.$
Now, $(487 - 437) - 1$
$= 50 - 1 $
$= 49$
Hence, the correct option is $(b).$
View full question & answer→MCQ 331 Mark
The predecessor of $1$ in whole numbers is:
AnswerPredecessor of $1 = 1 - 1 = 0$
View full question & answer→MCQ 341 Mark
The product of the predecessor and successor of an odd natural number is always divisible by:
AnswerThe predecessor of an odd number is an even number.
The successor of an odd number is also an even number.
These two even numbers are two consecutive even numbers, and the product of two consecutive even numbers is always divisible by $8.$
View full question & answer→MCQ 351 Mark
Every counting number has an infinite number of:
AnswerMultiples are what we get after multiplying the number by any number.
Thus, every counting number has an infinite number of multiples
View full question & answer→MCQ 361 Mark
The product of the successor and predecessor of $99$ is:
- ✓
$9800$
- B
$9900$
- C
$1099$
- D
$9700$
AnswerCorrect option: A. $9800$
We have:
Successor of $99 = 99 + 1 = 100$
Predecessor of $99 = 99 - 1 = 98$
Their product $= 100 \times 98 = 9800$
View full question & answer→MCQ 371 Mark
The product of the predecessor and successor of an even natural number is:
- A
Divisible by $2$
- B
Divisible by $3$
- C
Divisible by $4$
- ✓
AnswerEven natural number $= 2$
Predecessor of $2 = 2 - 1 = 1$
Successor of $2 = 2 + 1 = 3$
Their product $= 1 \times 3 = 3$
Thus, the product is an odd number.
View full question & answer→MCQ 381 Mark
Mark the correct alternative in the following: The number of whole numbers between the smallest whole number and between the greatest three digit number is:
AnswerThe smallest whole number is $0.$
Greatest three digit number $= 999$
The number of whole numbers from $0$ to $999$ is $1000.$
So, the number of whole numbers between $0 $ and $999 ($excluding $0$ and $999)$ is $1000 - 2 = 998.$
Hence, the correct option is $(c).$
View full question & answer→MCQ 391 Mark
The predecessor of $1$ in natural numbers is:
View full question & answer→MCQ 401 Mark
The number which when divided by $53$ gives $8$ as quotient and $5$ as remainder is:
AnswerHere, Divisor $= 53,$ Quotient $= 8$ and Remainder $= 5.$
Now, using the relation Dividend $=$ Divisor $\times$ Quotient $+$ Remainder
We get Dividend,
$= 53 \times 8 + 5$
$= 424 + 5$
$= 429$
Thus, the required number is $429.$
Hence, the correct option is $(c).$
View full question & answer→MCQ 411 Mark
The smallest natural number is:
- A
$1$
- ✓
$0$
- C
$-1$
- D
Non$-$existant.
View full question & answer→MCQ 421 Mark
The value of $4 \times 378 \times 25$ is:
- ✓
$37800$
- B
$3780$4
- C
$9450$
- D
$30078$
AnswerCorrect option: A. $37800$
By regrouping, we get
$4 \times 378 \times 25 $
$= 4 \times 25 \times 378$
$= 100 \times 378$
$= 37800$
Hence, the correct option is $(a).$
View full question & answer→MCQ 431 Mark
If two numbers are equal, then:
- ✓
Their $\ce{LCM}$ is equal to their $\ce{HCF}.$
- B
Their $\ce{LCM}$ is less than their $\ce{HCF}.$
- C
Their $\ce{LCM}$ is equal to two times their $\ce{HCF}.$
- D
AnswerCorrect option: A. Their $\ce{LCM}$ is equal to their $\ce{HCF}.$
If two numbers are equal, then their $\ce{LCM}$ is equal to their $\ce{HCF}.$
View full question & answer→MCQ 441 Mark
The product of the successor $999$ and predecessor of $1001$ is:
AnswerSuccessor of $999 = 999 + 1 = 1000$
Predecessor of $1001 = 1001 - 1 = 1000$
Now,
Product $= ($Successor of $999) \times ($Predecessor of $1001)$
$= 1000 \times 1000$
$= 1000000$
$=$ One million
Hence, the correct option is $(c)$.
View full question & answer→MCQ 451 Mark
Which of the following numbers is a prime number?
AnswerSince, factors of,
$91 = 1 \times 7 \times 13$
$81 = 1 \times 3 \times 3 \times 3 \times 3$
$87 = 1 \times 3 \times 29$
$97 = 1 \times 97$
Thus, $81, 87$ and $91$ all are not prime numbers.
View full question & answer→MCQ 461 Mark
The product of two numbers is $1530$ and their $\text{HCF}$ is $15$. The $\text{LCM}$ of these numbers is:
AnswerProduct of two numbers $= \text{HCF}$ of two numbers $\times \ \text{LCM}$ of two numbers.
$\Rightarrow 1530 = 15 \times \text{LCM}$ of two numbers
$\Rightarrow \text{LCM}$ of two numbers $= 153015 = 102$
$\Rightarrow 1530 = 15 \times \text{LCM}$ of two numbers
$\Rightarrow \text{LCM}$ of two numbers $= 153015 = 102$
View full question & answer→MCQ 471 Mark
The whole number $n$ satisfying $n + 35 = 101$ is:
AnswerHere, $n + 35 = 101.$
Adding $- 35$ on both sides, we get
$n + 35 + (-35) $
$= 101 + (-35)$
$n + 0 = 66$
$n = 66$
Hence, the correct option is $(d).$
View full question & answer→