Answer:
Tracy most likely saw 13 cars, and 13 motorcycles. Other solutions that you can find are: average number of tires in the area, the mode number of tires in the area (see the most often), etc.
Step-by-step explanation:
2x + 4x = 78
2(13) + 4(13) = 78
As 13 and 13 are two prime numbers, the answer will be 13.
