a car covers x km at 40 km/hr and another 2x km at 20 km/hr. find the average speed of the car in covering the entire 3x km. select one: a. 25km/hr b. 28km/hr c. 30km/hr d. 24km/hr
Answers
Answered by
2
Average speed = total distance / total time
Time = Distance / Speed
Time at 40 km/h is :
(x / 40) hrs
Time at 20 km/h is :
(2x / 20) hrs = x/10
Total time = x/40 + x/10 = x/8
Total distance = 3x
Average speed = (3x) ÷ x/8
= 3x × 8/x = 24
= 24 km/h
Similar questions