the growth of a new bacteria can be modeled by C(t)=100(1.03)^24t where C(t) is the total number of bacteria after t hours

Lizette is training for a marathon. at 7: 00 she left her house and ran until 8: 30, then she walked until 11: 30. she covered a total distance of 18 miles. her running speed was six miles per hour faster than her walking speed. find her running and walking speeds in miles per hour.