Skylar Greer

2022-12-26

What are the prime numbers between 20-30?

Dorian Beasley

Expert

The numbers between 20 and 30 are:
$21,22,23,24,25,26,27,28,29$
Since even numbers are by definition divisible by 2, all even numbers other than 2 are not prime. This leaves us with:
$21,23,25,27,29$
$21=3×7$ - not prime
$25=5×5$ - not prime
$27=3×9$ - not prime
This leaves:
$23,29$
For both of these numbers the only numbers they are evenly divisible by is 1 and themselves.
Therefore, $23$ and $29$ are the prime numbers between 20 and 30.

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