The organizer of a sports event estimates that if the event is announced x days in advance, the revenue obtained will be R(x) thousand dollars, where R(x)=400+10xx2. The cost of the advertising the event for is C(x)=x2+300. Get the profit function.

How many days in advance should the event be announced in order to maximize profit? (Get the vertex of the profit function and express the answer with one decimal place only)

How much is the maximum profit? (Express the answer with one decimal place only)

What is the ratio of revenue to costQ(x)=R(x)/C(x) at the optimal announcement time found in question 1? (Express the answer with two decimal places)