Answer:280 is the greatest value for this situation.
It cost 35 dollars per half hour to rent the JetSki. This means to rent the ski for one full hour, you would pay 70 dollars.
If you can rent the Jetski at a max of 4 hours this would be 70 x 4 which is 280. Lastly we must add in an insurance fee, which is a one time cost. 280 +15 is 195. This means our greatest value is 280, while the cheapest would be 50. (35+15)
I hope this helps & Good Luck <3 !!!