Answer:
72.5m/hr
Step-by-step explanation:
Divide 870 by 12 to represent how many miles David drove in 1 hour.

David drove 72.5 miles per hour.
Hey there!
To find the markup percentage, you must use your formula for percent markup:
profit/cost*100
Because your profit is found by subtracting 13-10, 3, your profit would be 3. You also know that your cost is 10.
Now, plug in your values:
3/10*100
And simplify:
3/10*100
0.3*100
=30
Therefore, your percent markup would be about 30%.
Hope this helps and have a nice day!
Answer: 
Step-by-step explanation:
This is a multiplication problem. You are multiplying
by 4. This also means 4 divided by 3. They are both the same.