Answer:
6 mph
Step-by-step explanation:
Difference in distance
= 15 - 12
= 3 mi
time taken
= 30 mins
= 1/2 hour
Speed
= 3 ÷ 1/2
= 6 mph
First find the amount of tax by multiplying 21 × 8.5%.
.085 × 21 = 1.785 = 1.79 (rounded)
Now add the tax back into the price...
21 + 1.79 = $22.79