You can
put this solution on YOUR website!The amount of tea is a volume. So, in order to scale, each of three dimensions must scale in the same ratio as the single dimension you are given.
All that ends up saying is "the change in volume is the cube of the change in a single dimension".
For instance, if the pot is changed from 10cm to 20cm, then the scale has doubled. So you need to cube that to get the volume. Thus, a 20cm high pot will brew

=

cups.
A 30cm high pot will brew

cups
Do that same type of conversion and you can find the two answers that "fit".
If you can't get them, let me know.