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 flowers in the vase is 5+6+7 = 18.
The probability of selecting the first carnation is 6/18 = 1/3.
After selecting the first carnation, there are 5 carnations left in the vase out of a total of 17 flowers.
So the probability of selecting a second carnation is 5/17.
Therefore, the probability of selecting two carnations is (1/3)*(5/17) = 5/51.