in Combinatory
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2 votes
2 votes
The answer given is 17.
in Combinatory
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1 Answer

4 votes
4 votes
Best answer

I guess question is "at least two cards each of two different kinds".

We can only have 13 cards of one kind. So, in the worst case we pick these 13 cards all of same kind. Now, if we pick the next card of a different kind, we can do like this only 3 more times- as there are only 4 different kinds. The fourth time we do, we must repeat a kind. So, 13+4 = 17 is the answer. 

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Don't Understand this line of explanation:
" Now, if we pick the next card of a different kind, we can do like this only 3 more times- as there are only 4 different kinds. The fourth time we do, we must repeat a kind."
After Picking 13 cards, isn't next card must be different kind for sure.
So answer should be 14.

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on the 14th pick, we guarantee at least 2 different suites- i.e., one card each from 2 different suites. But question is for at least 2 cards from 2 different suites.
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Got it.
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" So, in the worst case we pick these 13 cards all of same kind " Shouldn't this statement be " 13 cards of different kinds ", instead ?
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