are this numbers all the multiples of 3?

3. 6. 9. 12. 15. 18. 21. 24.

Yes, all of these numbers are multiples of 3 as they can be divided evenly by 3.

is 1 a multiples of 3?

No, 1 is not a multiple of 3 as it cannot be evenly divided by 3.

ok ty :)

You're welcome! If you have any more questions, feel free to ask. Have a great day! :)