Explanation

Numbers that can be divided by 1 or by themselves only = Prime number

Examples: 2, 3, 5, 7, 11...  

Like 7 ÷ 1 = 7 and 7 ÷ 7 = 1. No other number divides it exactly.

Even numbers can be divided by 2.

Last verified on 25-06-2026

Explanation

{1, 3, 5, 7, 9, 11, ...}  

These are numbers that cannot be divided by 2 without a remainder.  

1÷2 = 0 remainder 1, 3÷2 = 1 remainder 1, 5÷2 = 2 remainder 1...  

Numbers with remainder 1 when divided by 2 are called Odd numbers.  

Even numbers would be {2, 4, 6, 8...}.

Last verified on 25-06-2026

Explanation

( ) × 3 × 7 = 21  

( ) × 21 = 21  

So ( ) = 21 ÷ 21 = 1

Last verified on 16-06-2026

Explanation

• An irrational number cannot be expressed as a simple fraction.
• √2 is irrational because it cannot be expressed as a fraction of two integers.

Last verified on 16-06-2026

Explanation

• Odd numbers are integers that are not divisible by 2.
• They can be expressed in the form 2n + 1, where n is any integer.
• This formula always produces odd values like 1, 3, 5, 7, etc.

Last verified on 16-06-2026