A tourist covers half of his journey by train at 30 km/h, half of the remainder by bus at 30 km/h, and the rest by cycle at 10 km/h. The average speed of the tourist in km/h during his entire journey is:
A. 36 B. 30 C. 24 D. 18
GATE 2013 · General Aptitude · Speed Time Distance · easy
Answer: Average speed = 24 km/h (Option C). Train at 60 km/h, bus at 30 km/h, cycle at 10 km/h.
Set up distances for each segment: Let D = 120 km. Train: D/2 = 60 km. Bus: D/4 = 30 km. Cycle: D/4 = 30 km.
Compute time for each segment: Train: 60/30 = 2 h. Bus: 30/30 = 1 h. Cycle: 30/10 = 3 h. Total time = 2 + 1 + 3 = 6 h.