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5 votes
List all the numbers between 20 and 30 that are prime

2 Answers

5 votes

Answer:

23 and 29

Explanation:

We can cross out all the even numbers because they are all multiples of 2 so then we are left with: 21,23,25,27,29

We can use the divisibility rule for 3 which is to add the numbers in the number up and see if it can be divisible to 3

2+1=3

2+3=5

2+5=7

2+7=9

2+9=11

21 and 27 get crossed out

25 will get crossed out because any number that has a 5 or a 0 at the end is divisible by 5.

That leaves us with 23 and 29

They can't be divisible by 9,6,3,2,5,7,8 since the multiples of those numbers in the 20s do not match up with 23 or 29

So 23 and 29 is the answer

User Liubo
by
6.3k points
5 votes

the answer was 23, and 29

hope that helps you

User Woodrow Barlow
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6.2k points