Probability question (1 Viewer)

[BlueGas]

From a set of 4 cards, consisting of the Kings from a normal pack, 3 are chosen at random. Find the probability that the two red kings would be included in the 3 cards chosen.

 

[InteGrand]

From a set of 4 cards, consisting of the Kings from a normal pack, 3 are chosen at random. Find the probability that the two red kings would be included in the 3 cards chosen.

This is the same as just picking one card to 'discard', so that the remaining three are the 'chosen' ones.

So to have the two red Kings chosen, we are looking for the probability that we discard a black King. The probability of this is clearly 2/4, since there are 4 cards to pick the discarded one from, and 2 of them are black Kings.

So the answer is 2/4 = 1/2.

 

[BlueGas]

This is the same as just picking one card to 'discard', so that the remaining three are the 'chosen' ones.

So to have the two red Kings chosen, we are looking for the probability that we discard a black King. The probability of this is clearly 2/4, since there are 4 cards to pick the discarded one from, and 2 of them are black Kings.

So the answer is 2/4 = 1/2.

Damn, simple as that, I couldn't even figure to how to draw a tree diagram for this question, thanks man!