# Price discrimination question

For this question the answer is b which is the TR of group 2. If price is the same, my question is why isn't the demand function of group 1 considered? Why is the TR of group 1 omitted?

To sell 45 units to group 2 implies a price of $$220-2Q_2=130$$. At that price, demand from group 1 is zero. Indeed, the very most any consumer in group 1 is willing to pay is $$100$$.