Question

train travels at a speed of 60km/h at 0.52 h at 30 km/h for next 0.24h and then 70km/h for next 0.71h.find the average speed of car?

Answer 1

Step 1. Speed = Distansce/Time
          = 60 * 52/100 = 31.2km
similarly we will get 7.2km and 49.7km
Step 2. Avg Speed = 3xyz/x+y+z
[ x, y and z are speeds]
So the speeds in 1km will become   = 60/31.2, 
                                                         = 30/7.2 and
                                                         = 70/49.7
 Step 3.Applying values in the formulae
              = 3*1.92*4.2*1.4/7.52
              = 4.5 km/h