Question

boy travels 50 km with 5km/hr and then for next 4hr travels with a uniform speed of

20km/hr. What The average speed of the whole journey?

(A) 62/7km/hr (B) 65/7km/hr (C) 6017km/hr (D) 9km/hr​

Answer 1

Answer:

D

Step-by-step explanation:

Average speed formula is total distance by total time taken :)

Answer came out is 9.2857

If rounded answer will be 9 km/hr

Answer 2

Answer:

B=65/7 km/hr

Step-by-step explanation:

Average speed =total distance /total Time taken

Average speed =S1+S2/t1+t2

50+(20×4)/(50/5)+4

(Time =distance /speed)

(distance =speed×time)

50+80/10+4=130/14

130/14=65/7