3less than the quotient of 20 and x

Tom wants to order tickets online so that he and three of his friends can go to a water park the cost of the tickets is 16.00 per person there is also a 2.50 one-time service fee for ordering tickets online write an expression in term of n that represents the cost for n ordering tickets online

The measure of one angle of an octagon is two times smaller that of the other seven angles. what is the measure of each angle?

Yo need asap pls ! markin da brainiest too !