Hi, I have three Geometry questions on my quiz that I want to be absolutely certain they are done correctly, can someone help me with them please?

Anyone know? will mark brainliest if you're correct!

Donald has x twenty-dollar bills and 11 ten-dollar bill. how much money does donald have? write your answer as an expression.

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.