Given that probability of an event is 5/11. That means
Favorable number of events = 5
Total number of events = 11
Then unfavourable number of events = 11-5= 6
Now question says to find the "odds in favor" of the event occuring.
Which is given by formula:
Odds in favor of an event = [ number of favorable outcomes ] / [ number of unfavorable outcomes ]= 5/6
Hence final answer is 5/6
