This is a simple division problem. Since the car goes 228 miles in total at an average speed of 48 mph, you can plug 48/228 into a calculator and you'll get 4.75. The answer is 4.75 hours. Hope I helped!
The "trick" to making conversions, no matter how complex, is to use multiplication/division to introduce units you need for your final answer and eliminate or cancel out units you do not need for you answer.
