190mph
I used speed calculator with advanced mode
HTTP://www.omnicalculator.com/everyday-life/speed
Answer:

Step-by-step explanation:
15 Gallon of Gas costs $37.50
To determine the Unit Price, we divide the Total Cost by the number of gallons of gas bought.
Unit Price

That would be on the 5th week. There were 18 students that attended (D.)
Hope this helped!