Can some one help me on this math question its confusing ill give when right!!!

If eh = hg and hg=16, find the diameter of k

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.

Find the maximum value of p= 4x + 5y subject to the following constraints :