Question

A boy walks 1/3 of a journey at 6km/h ,1/4 of journey at 2km/h and rest at 4km/h.what is average speed of boy of the total journey ?

Answer 1

Answer:

Answer here ________________

Let the distance be xkm

Time taken for 1st =Distance /speed

=>x/3/6

=>x/18h

___________________

Time for 2nd part =Distance /speed

=>x/4/2

=>x/8h

_________________

Time for 3rd part =>Distance /speed

=>5x/12*4

=>5x/48h

________________

Average speed =Total distance /Total time taken

=>x/x/18+x/8+5x/48

=>144x/41x

=>3.5 km/h

hope helps ❤

Answer 2

Distance = xkm, time=dist/speed

1)x/3km/6=x/18hrs

2) x/4km/2 = x/8 hrs

Remaining dist::X-(x/3+x/4)

= x-(4x+3x)/12=5x/12

3) 5x/12 km/4=5x/48hrs

Average speed=x/x/18+x/8+5x/48

= 144x/41x=3.5 km/hr