"D-cup" also isn't enough information to gauge volume. A 36-D is larger than a 34-D. And remember that volume (and hence mass) increases as the cube of length, so two inches more in length will mean a lot more mass.
Either way, the numbers seem absurd.
Plugging in r1 of 3 and r2 of 2.5, and h1 of 36 and h2 of 34. Constants cancel out, that's an increase of 2.38 times in volume.
This is per cone ;)