Aferrari travels 250 km in 1.5 hours. approximately how fast is it going?
a. 167 km/h
b. 375 km/h
c. 0.006 km/h
d. not enough information

The phrase 'how fast is it going' refers to the speed of the vehicle. The speed is the ratio between the distance traveled and the time it takes to travel that distance. That is,
                                     s = d / t
where s is speed, d is distance, and t is time. The speed is calculated,
                                      s = 250 km / 1.5 h = 166.67 km/h

Thus, the answer is letter A. 

Efficiency is an action of doing something. for example when you take a test. good efficiency means you did well but bad effeciency or no effiency means you did bad.