How would I do this?

In the football stadium, there are 18 empty seats out of 360 total seats. (1a) write the ratio of empty seats to total seats as a fraction in simplest form. (1b) then explain its meaning.

Grace is standing 18 feet from a lighthouse and kelly is standing 10 feet from grace. the angle that grace looks up to see the top of the lighthouse is 45°. the angle that kelly looks up to see the top of the lighthouse is y°. find the height, h, of the lighthouse. find the angle, rounded to the nearest tenth of a degree, in which kelly looks up to the top of the lighthouse. to the nearest tenth of a degree, find the value of x° . in two or more sentences, explain your calculations

Can someone me find the original price? the discount is 5% and the sale price is $68.40