Question 303595
a car travels 2 3/4 hours at an average speed of 60 km/hour and then for 2 1/4 hours at an average speed of 80km/hour. whats is the average speed of the whole journey?


2 3/4 hours 60 km/hr

Distance traveled at this speed = 11/4 *60 = 165 km

2 1/4 hour 80 km/hr

Distance traveled at this speed = 9/4 * 80 = 180 miles

Total miles driven = 165+180= 345 km

Total time taken = 5 hours

Average speed for the total journey = total distance / total time = 345 / 5

69 km / hour

Ananth