Prime-Composite numbers

We at ask-math believe that educational material should be free for everyone. Please use the content of this website for in-depth understanding of the concepts. Additionally, we have created and posted videos on our youtube.

We also offer One to One / Group Tutoring sessions / Homework help for Mathematics from Grade 4th to 12th for algebra, geometry, trigonometry, pre-calculus, and calculus for US, UK, Europe, South east Asia and UAE students.

Affiliations with Schools & Educational institutions are also welcome.

Please reach out to us on [email protected] / Whatsapp +919998367796 / Skype id: anitagovilkar.abhijit

We will be happy to post videos as per your requirements also. Do write to us.

Prime-Composite numbers : This section explains you about Prime-Composite numbers.



Prime numbers: The numbers whose factors are 1 and the number itself is called Prime numbers.

Example : 2,3,5,7,11,13,…

2 is the smallest even prime number and 3 is the smallest odd prime number.

The prime numbers up to 100 are :

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71,

73, 79, 83, 89, 97

Composite Number : The number which has at least one factor other than 1 and the number itself.

Example : 4,6,8,9,12,…

Note : 1 is neither prime nor composite.
Co-prime Numbers : Two numbers that do not have a common factor other than 1.

The first 100 composite numbers are

4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20, 21, 22, 24, 25, 26, 27, 28, 30, 32, 33,

34, 35, 36, 38, 39, 40, 42, 44, 45, 46, 48, 49, 50, 51, 52, 54, 55, 56, 57, 58,

60, 62, 63, 64, 65, 66, 68, 69, 70, 72, 74, 75, 76, 77, 78, 80, 81, 82, 84, 85,

86, 87, 88, 90, 91, 92, 93, 94, 95, 96, 98, 99, 100, 102, 104, 105, 106, 108,

110, 111, 112, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125,

126, 128, 129.

Example : 35 and 39

35 = 7 x 5 x 1

39 = 3 x 13 x 1

Both 35 and 39 are composite numbers,the only factor common between them is 1.

∴ 35 and 39 are co-prime numbers.

Some more examples are : 1) 2,3 ; 2) 3,4 3) 5,6 4) 8,13, and so on.
Twin Primes : Two prime number are known as twin primes of there is only one composite number between them.

The twin primes between 1 to 100 are

3-5, 5-7, 11-13, 17-19, 29-31, 41-43, 59-61, 71-73

---

Factors and Multiples

• Prime-Composite numbers
• Divisibility rules
• Prime Factorization
• H.C.F or G.C.F
• L.C.M
• Application on LCM

Prime and composite numbers to Factors and Multiples

Number System

Home Page

Russia-Ukraine crisis update - 3rd Mar 2022

The UN General assembly voted at an emergency session to demand an immediate halt to Moscow's attack on Ukraine and withdrawal of Russian troops.