TYPES OF NUMBERS
PRIME NUMBERS : NUMBERS HAVING ONLY TWO FACTORS 1 AND NUMBER ITSELF IS ” PRIME NUMBERS”. PRIME NUMBERS ARE GREATER THAN 1.
For example 2,3,5,7,11,13,17,19, are prime numbers.
Key Point : 2 is the only even prime number.
There are 25 prime numbers from 1 to 100 . Read following table carefully.
| Numbers | Prime numbers |
|---|---|
| 1 TO 10 | 2,3,5,7 |
| 11 TO 20 | 11,13,17,19, |
| 21 TO 30 | 23,29 |
| 31 TO 40 | 31,37 |
| 41 TO 50 | 41,43,47 |
| 51 TO 60 | 53,59 |
| 61 TO 70 | 61,67, |
| 71 TO 80 | 71,73,79 |
| 81 TO 90 | 83,89 |
| 91 TO 100 | 97 |
coprime numbers :
consider 25 and 36 .
Factors of 25 = 1 ,5,25
Factors of 36 = 1 ,3,6,9,12,18,36
Among these factors , 1 is only common factor . So 25 & 36 are coprime numbers
Defination : If 1 is the only common factor , then those numbers are called coprime numbers.
