If y varies inversely as x, an d y = 12 when x = 6, what is k, the variation constant? a. 144 b. 72 c. 2 d. 1/3

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.