Question

Johny's journey Johny went to his uncle's house, riding his bicycle at 15 km/h and came back at 10 km/h. What's his average speed for the whole journey?​

Answer 1

Answer:

12km/h

Step-by-step explanation:

let x = 15 km/h and y=10 km/h

Average speed = 2xy/x+y

= 2×15×10/15+10

= 300/25

= 12

Hence the average speed of the whole journey is 12 km/h

Answer 2

Answer:

Let x=15 kmph and y=10 kmph

Average speed = x+y / 2xy

=

2×15×10 / 15+10

= 300/25

=12 kmph

Hence the average speed of the whole journey is 12 kmph