If an average-sized man with a parachute jumps from an airplane, he will fall 12.50(0.2t-1) +21t feet in t seconds. How long will it take him to fall 148 feet? (Round your answer to two decimal places.)

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.