They are apart by 3
This is correct. Two adjacent multiples of three will always differ by 3.
If I told you that 6 is a multiple of 3, then you know that
6 + 3 is the next-greater multiple of 3.
If I told you that 657 is a multiple of 3, then you know that
657 + 3 is the next-greater multiple of 3.
If I told you that x is a multiple of 3, then you know that
x + 3 is the next-greater multiple of 3.
If I told you that t/w is a multiple of 3, then you know that
t/w + 3 is the next-greater multiple of 3.
Now, please read your exercise again, and see if you understand it.
If you find that you're still confused, let us know exactly why.
Cheers ~ Mark :cool: