- #1
roadrunner
- 103
- 0
Hello everyone im' stuck on this problem.
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)
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)