Question

A train travels the distance of 15 kilometre inform speed of 30 km per hour next 75 km at 50 km per hour and last 10 km at uniform speed of 20 km per hour find the average speed for the entire journey

Answer 1

10km per hour will be the answer
because it is an individual series nd we can apply the formula of mean for individual series which as follows
mean=sum of all observations/no. of observations
here mean=100/10=10 km per hour