Correct Answer - Option 1 : 80 km/h
Given:
The total distance covered is 160 km
A part of the journey covered in 40 min
Another part of the journey covered in 80 min
Formula used:
\(Speed = \frac{{Distance}}{{Time}}\)
\(Average\;speed = \frac{{Total\;distance}}{{Total\;time}}\)
Calculation:
Distance of first part of journey = (3/4) × 160 = 120 km
Distance of second part of journey = 160 - 120 = 40 km
Total time (in minutes) = (40 + 80) min
⇒ Total time (in hours) = 120/60 = 2 h
⇒ \(Average\;speed = \frac{{120 + 40}}{2} = \frac{{160}}{2} = 80\;km/h\)
∴ The average speed of the journey is 80 km/h
