Anyone know what this is?

Nikolas calculated the volume of the prism. his work is shown below.

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.

Of the 304 people who attended a school play, 5/8 were students. how many of the people who attended were students.