How do you solve this (profit mazimization)?

Question

A monopoly has two production plants with cost functions C1 = 50 + 0.1 Q1^2 and C2 = 30 + 0.05 Q2^2. The demand it faces is Q = 500 - 10 P. What is the profit maximizing level of Q2?

Answer 1

impossible to answer.
you give two functions for the cost , ok
ypou give one function for the demand ok

But you do not give a function for the profit : you have to define the profit, we only know cost now , so what is the profit as function of the demand and as function of the costs ?