Write .00026 as a multiple of a power of 10

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?

15m is what percent of 60m; 3m; 30m; 1.5 km? the last one is km not m

Tan198=asin164=? how to solve this? ?