Question

3. A car first travels a distance 30 km with a speed 20 km h- and then a distance 45 km
with a speed 15 km h-I. Calculate :
(a) the total time of journey
(b) the average speed of car​

Answer 1

Answer:

a) 4.5 h

b) 17.5 km/h

Step-by-step explanation:

a) 30 km @ 20 km/h = 30/20 = 1.5h

45 @ 15 km/h = 45/15 = 3h

so, total time = 4.5h

b) 20+15 km/h = 35/2 = 17.5 km/h