A person covers a certain distance in 2 hours. If he had moved 5 km/h faster, he would have taken 30 minutes less. Find the original speed.
Show answer & explanation
Correct answer: C
Explanation
Given:
Distance covered = 2 hours
Increasing speed by 5 km/h = 30 minutes less time = 1.5 hours
Formula:
Distance = Speed × Time
Let initial speed = x km/h
Distance = 2x
New speed = x + 5
New distance = (x + 5) × 1.5
Both distances are equal, so
2x = 1.5(x + 5)
2x = 1.5x + 7.5
2x − 1.5x = 7.5
0.5x = 7.5
x = 15 km/h