10/3 times what equals 20

Is it true or false i’m trying to pass this test so i can leave school

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?

If g^-1(x) is the inverse of g (x) which statement must be true