Answer:
4/5
Step-by-step explanation:
The bus may leave at 11:45, or 11:46, or 11:47, or 11:48, or 11:49.
If he catches the 11:45 bus, he arrives at his friend at 11:57 and makes it.
If he catches the 11:46 bus, he arrives at his friend at 11:58 and makes it.
If he catches the 11:47 bus, he arrives at his friend at 11:59 and makes it.
If he catches the 11:48 bus, he arrives at his friend at 12:00 and makes it.
If he catches the 11:49 bus, he arrives at his friend at 12:01 and does not make it.
p(making it on time) = 4/5
