Question

a boy go from home to school at the speed of 40 kilometre per hour and come back from home at the speed of 30 km per hour find the average of the boy​

Answer 1

Answer:

Speed, v1 = 40 km/hr

v2 = 30km/hr

VAvg = 40 + 30 / 2 = 70/2 = 35 km/hr

VAvg = 35 km/hr

Answer 2

Answer:

34.28kmph

Explanation:

assume distance home to school X

total distance =2x

time for onward X/40

time for return X/30

avg Speed = total distance /total time

34.2

= 2x. /(x/40+x/30)

=2x/ (70x /1200)

= 2400/70=34.28

you can assume distance between school & home is 120km. ( lcm 3,4=12. and multiply o by ten for our learning)

now onward time = 120/40=3 hrs

return = 120/30 =4 hrs

total distance = 120+120 =240

total time = 3+4=7hrs

avg speed, 120/7= 34.28