A big flower vase has 5 begonias, 6 carnations, and 7 tulips. Two flowers are randomly selected without replacement. What is the probability of selecting two carnations? Express the answer in the simplest form of fraction. (1 point)
The total number of ways to choose 2 flowers out of 18 flowers is 18 choose 2, which is calculated as:
18! / (2!*(18-2)!) = 153
The total number of ways to choose 2 carnations out of 6 carnations is 6 choose 2, which is calculated as:
6! / (2!*(6-2)!) = 15
Therefore, the probability of choosing 2 carnations is:
15 / 153 = 5 / 51
So, the probability of selecting two carnations is 5/51.