David and Jim like to race each other for best times. In April, the ratio of David winning to Jim was 5 : 9. In August, the ratio changed to 10 : 4. If David won 15 races in April, how many races did each brother win in August?

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?