If a car travels for 20km at 60km/h and then another 30km at 90km/h, what is the average speed of the journey? Round your answer to 2 decimal places.

75.00 km/h.

Step-by-step explanation:

Average speed of the journey = total distance / total time taken.

The first part of the journey:

60 = 20/time

60 * time = 20

time = 20/60 =

Second part: 1/3 of an hour.

90 = 30 / time

time = 30/90 = 1/3 of an hour.

So the total distance is 50 km and the total time is 2/3 hours.

Therefore the average speed

= distance / time

= 50 / 2/3

= 150/2

= 75.00 km/h.