Answer:
<h2>B. The amount of fuel used was lowest at speeds around 60km/h.</h2>
Step-by-step explanation:
The decreasing part is from (20,13) to (60,6), which gives an average rate of

Then, we have an increasing part from (60,6) to (120,10), which gives an average rate of

Basically, at 60 km/h the fuel used was 6 liters per 100 kilometers. Notice that the other velocities make the car to use more liters per kilometers.
Therefore, the amount of fuel used was lowest at speeds around 60 km/h.
Perimeter of the carpet = 21.8 m
Area of the carpet = 
<u>Given</u>:
<em>Dimension of the living room:</em>
<em />
<em>A. </em><em>Perimeter </em><em>of the carpet = perimeter of a </em><em>rectangle</em>
Perimeter = 
Substitute

Perimeter of the carpet = 21.8 m (The digits here are significant)
<em>B. </em><em>Area </em><em>of the carper = </em><em>area </em><em>of a </em><em>rectangle </em>
Area = 
Substitute

Area of the carpet =
(the digits here are significant)
Therefore, considering the rules of significant digits:
Perimeter of the carpet = 21.8 m
Area of the carpet = 
Learn more here:
brainly.com/question/12932084
Answer:
tip amount = $23.68
Step-by-step explanation:
t = tip percentage (as decimal, so 5% would be 0.05)
c = cost
tip amount = c * t
tip amount = (118.40) * (0.20) = $23.68
hope this helps :)