Question

2) A car covers one-fourth of a distance at a speed of
100 km/hr, half of the remaining distance at a speed of
60 km/hr and the remaining distance at a speed of
100 km/hr. If the total time taken to complete the journey
is 10 hours, then what is the average speed of the car?
A) 80 km/h
B) 72 km/hr
C) 75 km/h
D) 64 km/hr​

Answer 1

let total distance be x

it covers ;

■ x/4 at 100km/hr

■ (x_x/4)/2 = 3x/8 at 60km/h

■ remaining 3x/8 at 100 km/h

using formula

distance / speed = time

we get the average speed = 80km /h