A CAR IS DRIVING AT 60 KM/H FOR 20 MINUTES, AND THEN DRIVES AT 90K...

30. - PROBLEMS PRACTICE PHẦN 10 PPSX
PROBLEMS PRACTICE PHẦN 10 PPSX
30. A car is driving at 60 Km/h for 20 minutes, and then drives at 90Km/h for another 40 minutes. What is the average speed of the car? (a) 80. (b) 75. (c) 70. (d) 65. (e) 54.