A taxi covers a certain distance in 20 min if it runs at a speed of 60 km/h. What must be the speed (in km/h) of the taxi in order to increase the time of the journey from 20 min to 30 min?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 40.
Initial speed =60 km/h
Initial time =20 min =1/3 h
Distance = 60 ×1/3 = 20 km
New time = 30 min = 0.5 h
New speed = 20/0.5 = 40 km/h