Correct option is B
Solution:
Buses for Town A arrive at: 00:10, 00:30, 00:50, …
Buses for Town B arrive at: 00:15, 00:35, 00:55, …
The combined pattern repeats every 20 minutes.
Consider one 20-minute cycle from 00:10 to 00:30:
· From 00:10 to 00:15 → next bus is Town B (5 minutes)
· From 00:15 to 00:30 → next bus is Town A (15 minutes)
Total interval = 20 minutes
Probability that the next bus is for Town B = 5 / 20 = 1/4
Correct answer: (b) 1/4


