Data Sufficiency (DS) | Re: A lottery is played by selecting X distinct single digit numbers from

Thanks Bunuel!
I get it now. The four ways to pick a combination with exactly one overlap are mutually exclusive events and hence need to be added to arrive at the overall probability of the events where there's exactly one overlap.

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Statistics : Posted by Cuttlefish • on 05 Feb 2013, 07:40 • Replies 13 • Views 25139

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