There are 5 Merlot and 7 Cabernet bottles. Since all bottles look alike,
(a) the probability for the first bottle being Merlot is 5/12. If one bottle drawn out of 12(which is a Merlot), there are 11 bottles left and your probability for the second bottle being Merlot is (4/11). Likewise, the third one being Merlot is (3/10)
use the same concept for (b) and (c) and show your work if you have any queries!