MATHS M.C.Q. [1 Marks Each]

 Let an odd natural number other than $1$ be $3.$
Then, predecessor of $3 = 3 - 1 = 2$ and successor of $3 = 3 + 1 = 4$
$\therefore$ Their product $ = 2 \times 4 = 8$
$LCM$ of predecessor and successor i.e.
$\begin{array}{c|c}2&2,4\\ \hline2&1,2\\ \hline&1,1\end{array}$
$= 2 \times 2= 4$
Hence, the greatest number which always divides the product of predecessor and successor of an odd natural number other than $1,$ is $4.$

 The smallest three-digit number is $100 $ and the largest two-digit number is $99.$
$\therefore$ Difference $= 100 - 99 = 1$

$1\text{m}^{2}=$ $1\text{m}\times1\text{m}=100\text{cm}\times100\text{cm}=10000\text{cm}^{2}$

 $1000 \text{m}=1\text{km }10060$
$\text{metres}=\frac{10060}{1000}\text{km}$
$={10}.{06}\text{km}$

$ M = 1000, C = 100, X = 10, I = 1$
$2440 = 2000 + 400 + 40$
$= 2000 + (500 - 100) + (50 - 10)$
$= MMCDXL$
$2440 = MMCDXL$

 We know that, $1$ million $= 1000000 = 10$ lakh

$ = 3000000 − 300 = 2999700$

 We know that, the successor of a whole number is the number obtained by adding $1$ to it and the predecessor of a whole number is one less than the given number.
So, the successor of $999 = 999 + 1 = 1000$ and the predecessor of $999 = 999 - 1 = 998$
Product of successor and predecessor of $999 = 1000 \times 998 = 998000$

We know that, the symbols $V, L$ and $D$ can never be repeated.
So, $LLX$ is incorrect.

$800m, 200m$
$100m = 0.1m$
$1m =\frac{0.1}{100}\text{m}$
$200m= \frac{0.200}{100}\text{m}$$= 2m$

$\text{HM TM M HL TL L H T U 5 0 0 , 0 0 0 , 0 0 6}$

To round of the given no in nearest lakh we need to see the value at ten thousand place which is $6$ it is more than $5.$
So we round off lakhs digit to $5 + 1 = 6$
So we will round off. $38,65,62,048$ will become $38,66,00,000$

The given number is $9798745995.$
As per the international place value system, the number can be written as: $9,798,745,995$
Hence, $9798745995$ is written with periods in international system as $9,798,745,995.$

We know that
$X = 10, C = 100$
Therefore, $XC = 100 - 10$

 The number just before $1000000$ is $999999 (i.e., 1000000 - 1).$

In $2985$ the last two digits i.e., $85$ is greater than $50.$
Hence, $1$ will be added to the $3rd$ last digit and the last two digits will become zero.
After rounding to nearest hundred we will get $3000.$
Again, In $2985$ the last digit i.e., $5$ is equal to $5.$
Hence, $1$ will be added to the $2nd$ last digit and the last digit will become zero.
After rounding to nearest ten we will get $2990.$
Required difference $= 3000 - 2990 = 10$
Hence, the correct answer is option $(c).$

To form the greatest $5$ digit number we write the given numbers in descending order.
The number we form is $97520.$

An $8$ digit number starts with ten millions place in the international system.
$Ex: 10,000,000$

 The total length of the line is $400m.$
we know $1$ centimeter $=10$ millimeters
$1\text{mm}=\frac{1}{10}\text{cm}$
We have to convert the $400$ mm to $cm$.
$400\text{mm}=\frac{1}{10}\times400\text{cm}$
$=\frac{400}{10}\text{cm}$
$=40$ centimeter
The line is $40\ cm$ long

 To get predecessor of a number, we subtract $1$ from the given number.
So, the predecessor of $1$ lakh $= 100000 - 1 = 99999$

 According to the Indian system of numeration, the number $58695376$ will be written as
$5, 86, 95, 376$
Note In Indian system of numeration, we use different periods like ones, thousands, lakhs, crores, etc., to read the large number easily. $A$ comma $(,)$ is used to differentiate the periods. There are two places in each period except ‘units’.

 In Roman numerals, $V, L$ and $D$ are never repeated and never subtracted.

 Speed of train $=63\Big(\frac{\text{km}}{\text{hr}}\Big)$
$=\Big(\frac{63.100}{3600}\Big)$
$=17.5\big(\frac{\text{m}}{\text{s}}\big)$
By passing a tree,train will have to cross its own length
$\therefore$ Time taken $=\big(\frac{280}{17.5}\big)$$={16}\text{sec}$

 Divide the numbers in groups of $3$ starting from right. herefore,$185,367,249.$

 Place value of $6 = 6$ lakhs
$= (6 \times 100000)$
$= 600000$

 In units place, $i.e., 9, 19, 29, 39, 49, 59, 69, 79, 89, 99$
$9$ occur $10$ times
In ten's place i.e., starting from $90$ to $99,$
$9$ occur $10$ times
$\therefore$ Total $= 20$ times
Hence, the correct answer is option $(d).$

 Of the two lengths given in the problem, one is inches and the other is in feet.the answer needs to be inches,
so convert the length of the board to inches. since there are $12$ inches in one foot, the $4 -$ foot board is 48 inches long.
now subtract the length of the piece the carpenter cut off.$48 - 1.3 = 46.7$

 The sum of $10$ and $40$ is,
$10 + 40 = 50$
$50$ is written as the symbol $L$ in Roman numerals.

 The given sequence is: $738, 429, 156, 273, $ After reversing the digits,
The sequence becomes : $837, 924, 651, 372, 498.$
The second highest number is $837$ and its last digit is $7.$

The numbers are $359, 395, 539, 593, 935, 953.$

To form the greatest $5$ digit number we write the given numbers in descending order.
The number we form is $97520.$

Since, even numbers between $58$ and $80$ are $60, 62, 64, 66, 68, 70, 72, 74, 76$ and $78.$
Total even numbers between $58$ and $80 = 10$

There are seven basic Roman Numerals.
They are $I, V, X, L, C, D$ and $M.$
These numerals stand for the number $1, 5, 10, 50, 100, 500$ and $1000$ respectively.

$1$ Feet $= 0.3048m$

In international number system $10$ million $= 10,000,000$
$\therefore$ there are $7$ zeros come after $1$ in $10$ million

$1$ Million $= 10,00,000$
$\Rightarrow 90$ Million $= 90 \times 10,00,000 = 9,00,00,000 .....(1)$
$1$ thousand $= 1,000$
$\Rightarrow 90$ thousand $= 90 \times 1000 = 90,000 .....(2)$
$\Rightarrow $ Ninety can be written as $= 90 .....(3)$
Adding $(1), (2)$ and $(3)$ we get, $\Rightarrow 9,00,00,000 + 90,000 + 90 = 9,00,90,090$
$\therefore$ Numeral for ninety million ninety thousand ninety is $9,00,90,090$

Smallest three digit number which can be formed is if we arrange them in ascending order, i.e. $479$
Hence $479$ is the smallest three digit number.

$9,499$ is the greatest number that when rounded off to the nearest thousand will become $9,000.$
$8,500$ is the smallest number that when rounded off to the nearest thousand will become $9,000.$
$\therefore$ Difference $= 9,499 - 8,500 = 999$