**Number System Aptitude Questions And Tricks**

What is Number System in Maths? A number framework is characterized as an arrangement of composing for communicating numbers. It is the numerical documentation for speaking to quantities of a given set by utilizing digits or different images in a predictable way.

**NUMBER SYSTEM** APTITUDE QUESTIONS

1. A man spends 1/3 of his income on food, 1/4 of the rest on house rent and 1/5 of the rest on clothes. He still has Rs. 1,760 left with him. Find his income?

Explain:- As per the question, Let the total income be x. Income spent on food=1/3 of x= x/3. Remaining= x-x/3=2x/3. Income spent on rent= 1/4 of 2x/3=x/6. Remaining=2x/3-x/6=x/2. Income spent on clothes=1/5 of x/2= x/10. Remaining=x/2-x/10=4x/10. Also Remaining income=1760Rs. So, 4x/10=1760. =>4x=1760×10=17600. =>x=17600/4. =>x=4400Rs. His total income is 4400Rs. Hope it helps

2. A lamp post has half of its lenght in mud, 1/3 of its length in water and 3 1/3 m above the water.Find the total length on the post.?

Explain:- As per the question, Let the total length of the post b x m Then length of post in mud = x/2 Length of post in water = x/3 Given = x/2-x/3 = 3 1/3= 10/3 x/6 = 10/3, X = 20m Hope it helps

3. I collected some money by raising subscription for opening a library. If the whole amount collected be Rs720 currency notes of 1000 denomination and each person subscribed as many rupees as twice the number of subscribers find the amount paid by each Subscriber.?

Explain:- As per the question, Let us consider the amount paid by each of the x number of subscribers be Rs. y Then total fund collectioned = Rs. xy By the given condition, the money paid by each subscriber = twice the number of subscribers, and this implies y = 2x ..... (1) ATQ, xy = 720 X 1000 or, x (2x) = 720000 or, x² = 360000 or, x = 600 Then the number of subscribers is 600 and money paid by each of them is Rs. (2 X 600), i.e., Rs. 1200 Hope it helps

4. A number when divided by 342 gives a remainder 47 When the same number is divided by 19 what would be the remainder.?

Explain:- As per the question, On dividing the given number by 342, Let K be the Quotient and 47 is remainder Then number = 342K + 47 (19 X 18K + 19 X 2 + 9) 19 (18K + 2) + 9 The given number when divided by 19 gives 18K + 2 as quotient and 9 as reminder. Hope it helps

5. The sum of first 20 odd natural number is.?

Explain:- As per the question, First 20 odd natural numbers: First term, a=1 Common difference, d=2 Sum of first n terms of and AP: n/2 (2a+(n−1)d) Here, n=20,a=1,d=2 Substituting these, we get Sum of first 20 natural numbers: 20/2 (2(1)+(20−1)2) =10×(2+19×2)=10×40=400 Hope it helps

**How Many Types Of Number System **

The number framework incorporates various sorts of numbers for instance indivisible numbers, odd numbers, even numbers, judicious numbers, entire numbers, and so forth These numbers can be communicated as figures just as **How Many Types of Number System** words appropriately. For instance, the numbers like 40 and 65 communicated as figures can likewise be composed as forty and 65.

A Number framework or numeral framework is characterized as a rudimentary framework to communicate numbers and figures. **How Many Types of Number System** It is the special approach to addressing of numbers in math and arithmetical design.

Numbers are utilized in different math esteems appropriate to do different number-crunching activities like expansion, deduction, increase, and so on which are relevant in regular routines with the end goal of estimation. **How Many Types of Number System **The worth of a still up in the air by the digit, its place esteem in the number, and the foundation of the number framework. Numbers by and large are otherwise called numerals are the numerical qualities utilized for counting, **How Many Types of Number System** estimations, marking, and estimating basic amounts.

**How Many Types Of Number System **

**Whole Numbers:** The set of whole numbers is denote by “W”.

- where “W” = { 0, 1, 2, 3, 4, 5, 6, …….}

**Natural Numbers**: The numbers which are use in counting are known as Natural Numbers or Positive Integers. Their set is denote by N.

- Thus, N = { 1, 2, 3, 4, 5, 6, …….}

**Set of Integers:** All counting numbers. Their negatives and “O”, when combined from the set of integer. This is denote by I.

- Thus I = ( ………… -3, -2, -1, 0, 1, 2, 3, ………….)

**Even Numbers:** Those numbers which are exactly divisible by 2 are known as even numbers.

- For example 2, 4, 6, 8, 10, …………

**Odd Numbers:** The numbers which are not exactly divisible by 2 known as Odd Numbers.

- Ex: 1, 3, 5, 7, 9, ……….

**Prime Numbers: **A number is said to be a Prime Number if its factors are “1” and the number itself only.

- Ex: 2, 3, 5, 7, ……..

There are 25 prime numbers below 100.

**Composite Numbers **: The numbers which are not Prime are call “Composite Numbers”.

- For example 4, 6, 8, 9, 12, ……….

**Rational Numbers:** A number of the form a/b where a and b are integers prime to each other b ≠ 0 is called a Rational Numbers.

**Irrational Numbers**: The numbers whose exact value cannot be determine are call Irrational Numbers.

- For example √3, √5, √7, ……etc.

**Real Numbers**: Both Rational and Irrational Numbers are collectively known as Real Numbers.

### Test of Divisibility

- A number is divisible by 2, if its units digit is 0 or even.
- 2) A number is divisible by 3, if the sum of the digits can be divide by 3.
- 3) A number is divisible by 4, if the number compose of the last two digits can be divide by 4 or the last two digits are zeros.
- 4) A number is divisible by 5, if the last digit is either 0 or 5.
- 5) A number is divisible by 6, if it is divisible by both 2 and 3.
- 6) A number is divisible by 8, if the number compos of the last three digits can be divide by 8 or the last three digits are zeros.
- 7) A number is divisible by 9, if the sum of the digits can be divid by 9.
- 8) A number is divisible by 11, if the sum of the digits in the odd place so the number and the sum of the digits in the even places are equal or the difference of these two sums is divisible by 11.
- 9) A number is divisible by 12, if it is divisible by both 3 and 4.
- 10) A number is divisible by 25, if it ends in '25', '75', '00'.

**Number System Aptitude Questions And Tricks**