The speed of a car is 70 km in the first hour and 90 km in the second hour. What is the average speed of the car?	Choose the correct choice from the following answers:
A) 79 kmph B) 80 kmph C) 34 kmph D) 23 kmph E) 14 kmph

Rationale: "s = ( 70 + 90 ) / 2 = 80 kmph answer : b"
Answer: B