Question

A man covers a distance of 40km.He covers first 10km at 10km/h, second 10 km at 20km/h, third f okmat 30km/h and last 10km at 40km/h. What is the average speed of man? (a) 18.2 km/h (b) 19.2 km/h (c) 19.0 km/h (d) 16.2 km/h

Answer 1

Answer:

(a) 19.2

Step-by-step explanation:

Time taken for 1st 10km = 10/10 = 1hr

Time taken for 2nd 10km = 10/20 = 0.5hr

Time taken for 3rd 10km = 10/30 = 0.33hr

Time taken for last 10km = 10/40 = 0.25hr

Total time taken = (1+0.5+0.33+0.25)hrs = 2.08hrs

Total Distance = 40kms

Average speed = total distance /

Total time taken

40/2.08 = 19.2