Hello, thank you for taking the time to post your question!
The key on this type of question is to use the information given in the word problem in order to set up an equation. On this one that becomes
miles per gallon = total miles / total gallons
=296 / (14_8/10)
=20
So the car in this scenario got 20 miles per gallon
I hope that helps get you moving in the right direction! Feel free to reach out if you have any additional questions beyond that :)