The speed of a car is 90 km in the first hour and 80 km in the second hour. What is the average speed of the car?
Options:
A) 12
B) 75
C) 85
D) 54
E) 15
S = (90 + 80)/2= 
<gadget id="calculator">(90 + 80)/2</gadget>
<output>85</output>
85 kmph   Answer: 85
<result>C</result>
The speed of a car is 90 km in the first hour and 80 km in the second hour. What is the average speed of the car?