Eric Nicholas K's answer to Xiang Ning's Junior College 2 H2 Maths Singapore question.
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Not 100% sure about part b.
Date Posted:
4 years ago
Can there be a case where 1 of the letters is E and the rest are non-Es?
For case 3, is it possible to have no Es at all?
Basically my case 3 is for all different letters. This third case includes the 1E case and the no E case, since a non-repetition of E would make E no different from any letter in a seven-letter selection of letters.
However, you can feel free to split case 3 into two further cases of 1E and no E.
The question has no restriction on the use of Es, only the restriction on choosing exactly 3 letters available out of 9.
However, you can feel free to split case 3 into two further cases of 1E and no E.
The question has no restriction on the use of Es, only the restriction on choosing exactly 3 letters available out of 9.
Alright, thank you
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