Two-part Analysis | Re: A sock drawer contains 36 pairs of socks, which are colored white, bro

We know there are 36 pairs of socks

total 'colors' = 25 + 28 + 20 = 73

If 5 socks have all 3 colors, we know 5 pairs are counted in all 3 buckets, and we should de-duplicate by subtracting 5 * 2 = 10 - so we get 63 pairs...

But wait! this is much more than our total of 36 socks. So we need to find how many are still double counted. If a sock has 2 colors it is counted twice in our 63 color total, so to get the number of 2-color pairs we can do total colors - total socks = 63 - 36 = 27 - we know 27 pairs have 2 colors, and that gives us our answer for that part.

For the number of 1 color socks, we can do total - 3 color - 2 color or 36 - 27 - 5 = 36 - 32 = 4 pairs!

And this makes sense - if we have 73 total colors, we can do 4 + 27*2 (27 pairs w 2 colors) +5*3 (5 pairs w 3 colors) = 4 + 54 + 15 = 73

Statistics : Posted by brp616 • on 18 Dec 2023, 12:51 • Replies 1 • Views 72

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