a car travels 35 km in the first 20 minutes, 43 km in the second 30 minutes and 19 km in the last 18 minutes of a trip. what is the average speed in Km/mn?
35 + 43 + 19 = 97 km
20 + 30 + 18 = 68 mn
97 / 68 = 1.426 km/mn
20 + 30 + 18 = 68 mn
97 / 68 = 1.426 km/mn