Hello everyone im' stuck on this problem.(adsbygoogle = window.adsbygoogle || []).push({});

It says:

Each symbol in braille code is represened by a rectangular arrangement of six dots. Given that a least 1 dot of the 6 must be raised, how many symbols can be represented in brail?

now i saw this posted somewhere else, they got 63. don't know how.

i got 63 two ways....

2^6-1 (case where all down)=63

6c1+6c2+6c3+6c4+6c5+6c6 -1 also =63 (where 6c3 etc is combinations...6 options choose 3)

can sumone explain how/why that works please.

also part b...how many combinations have EXACTLY 3 raised

and how many have an even number of raised dots

(this is for math and computer science course so not TOO sure which to post it in thanks)

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# Homework Help: Permutations/combinations with Braille dots

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