The graph below represents a rock climbers height as she acends a hill. Part A- The above graph is (circle one) linear/ nonlinear. Part B- Is the above graph a function? Explain.

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.