A caterer normally charges $15 per person plus a $10 delivery fee for 'in-advance' orders but charges $20 per person plus a rush delivery fee for same-day orders. If Amy places a same-day order for her company, by what percent is her total cost greater than if she had placed the same order 'in advance'?

(1) The rush delivery fee is $20.

(2) Amy places an order for 10 people.

[spoiler]OA=C[/spoiler]

Source: Veritas Prep