Pl help it’s for a grade

Which is the correct excel formula for the 80th percentile of a distribution that is n(475, 33)? =norm. dist(80,475,33,1) =norm. inv(0.80,475,33) =norm. s.inv((80-475)/33)?

You are at a restaurant and owe $38 for your meal. you want to leave a 20% tip. how much will your tip be?

Sarah took the advertising department from her company on a round trip to meet with a potential client. including sarah a total of 11 people took the trip. she was able to purchase coach tickets for $280 and first class tickets for $1280. she used her total budget for airfare for the trip, which was $6080. how many first class tickets did she buy? how many coach tickets did she buy?