I assume the modifiers come from the Technician ability and the applied STAB that Roserade receives.
Technician increases the power of moves which have a power of 60 or less by 50%.
The ability increases power by 50%, or multiplies it by 1.5. Then Roserade would receive STAB, which multiplies damage by 1.5:
Same-type attack bonus [...] is a 50% damage boost of an attack when it is the same type as one of the types of the Pokémon using the attack.
Thus, the logic of the second scenario would occur and the resulting power would be 60 × 1.5 × 1.5 = 135.
Hope I helped. :)
Source: Bulbapedia's pages on Technician and STAB