Solution to example 2 above is not understood, especially the third and fourth lines please explain as i hav e to finish the eleventh syllabus and start with twelveth, so please JALDI.

See, we are left with only 50 cards to choose from, so we can choose 8 black cards out 50 in ways . 

Now, probability of getting atleast 2 black cards means we have to calculate probability of getting two or more than 2 ( or we have to calculate by considering all the probabilities of getting 2 or 3 or 4 or 5 or 6 or 7 or 8 black card).

Doing it in this manner will make the calculation tedious for us, so we follow another approach, that is, 

Probability of getting atleast 2 black cards = 1 - Probability of getting atmost 1 black card) = 1 - Probability of getting 0 black card or only 1 black card)  

Now, here if we do not select any of the black card then all the eight cards selected will have red color.

Similarly, if only 1 black card is selected out of the 8, then all the other 7 cards will be of red color.

Also, remember that there are 26 cards of black color and 26 cards of red color each.

Now you can try and solve the question on your own by considering this explanation and the solution side by side.

Hope you are able to understand the same. If still any doubt persists, do let us know.