What's the equation of pie divided by 12 ?

Which equation represents the partial sum of the geometric series?

Which part of a 2-column proof is the hypothesis of the conjecture? a) given b) reasons c) prove d) statements ! i think it's b but i'm not quite

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?