1. Erm, if its [B]between[/B] 0 to 100, then you should'nt take into account numbers 0 and 100 *I think, not very sure.*
2. I'l be back soon to help out....
(a) Read again, they gave five letters but ask choose four out of it. So (a) should be 5P4, with the answer of 70.
2c (1 x 4 x 3 x 2) A being in the first slot + (4 x 1 x 3 x 2) A in the second slot + (4 x 3 x 1 x 2) + (4 x 3 x 2 x 1), so
4 x 4 x 3 x 2
2d (1 x 5^3) A in the first slot + (5 x 1 x 5^2)etc. etc.
4 x 5^3
...
"(5)<SUBSCRIPT>4=5*4*3*2=120"
What is this weird notation?
This is usually denoted 5!
[QUOTE=JohnnyMo1;34713647]"(5)<SUBSCRIPT>4=5*4*3*2=120"
What is this weird notation?
This is usually denoted 5![/QUOTE]
It's not a factorial, it's the number of possible permutations of length 4 that you can do with 5 digits. It's usually denoted nPk and it's equal to n!/(n-k)!. Here 5-4 is 1, that's why it's equal to 5!
Never seen that "subscript" notation though.
Ah, I see. I misread the problem.
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