Average speed = total distance divided by total time.
In the first part, the car covered 490 km in 7 hours, but I think you mistyped the second part (“then covers a speed of 90km”) and a critical piece is missing to find the total distance and time.
Answer:
Each t-shirt cost 13 dollars.
Step-by-step explanation:
Since the jacket was 20 bucks, we can set that aside:
85-20=65
Now that we've set that aside, there are five t-shirts. If they all cost the same, that means we can divide!
65/5=13
How to check?
Use inverse operations: 13*5=65
Re-add the 20 bucks from the jacket, and the bill is complete again! Use inverse operations: 13*5=65
Each shirt costs $13.