Shelly completed 10 problems of her homework in study hall. thi sis 2/7 of the total assignment. how many problems does she have left to complete

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.