A person takes 2 hours to travel a certain distance by scooter. Returning over the same distance, he increases his speed by 10 km/h and takes 1.6 hours. What was his original speed?
Show answer & explanation
Correct answer: A
Explanation
Let the original speed be x km/h.
Distance while going = x × 2 = 2x
Speed while returning = x + 10
And time = 1.6 hours
Therefore, return distance = 1.6(x + 10)
The distance is the same in both cases; hence,
2x = 1.6(x + 10)
2x = 1.6x + 16
0.4x = 16
x = 40 km/h