Answer:
Let number of friends Olive has = S
She wants to select a friend for a trip.
1. Probability of selecting a friend out of S friends
Ok, suppose out of S friends P are male and Q are female.
S=P +Q
2. Probability of selecting 1 male friend out of S friends which includes P male and Q female
3. Probability of selecting 1 Female friend out of S friends which includes P male and Q female
These three are random methods.Other methods of finding probability of choosing a friend can be non Random.