I need help on a math problem. It is:
At 9 A.M. a test car driving at a constant speed passes a marker 50 miles from it's starting point. At noon the car is about 130 miles from the marker. If the test drive ends at 1:30 P.M., how far will the car be from its starting point?

Thank you if you can help,
Jennie

You are measuring two quantities, time and distance and the trip is divided into three segments. The first segment is the first 50 miles, the second segment is the next 130 miles and the last segment is an unknown distance. I see this as a diagram

In the first segment you travel 50 miles in an unknown time and in the last segment you drive for an hour and a half for an unknown distance. In the center segment however, you know both the time and distance, you travel 130 miles in 3 hours. Thus your speed is  ¹³⁰/₃ miles per hour. At that speed how far do you go in the last hour and a half, from noon until 1:30.