MHB Combination Problem: C(70,67) = 54,740

  • Thread starter Thread starter yakin
  • Start date Start date
  • Tags Tags
    Combination
yakin
Messages
42
Reaction score
0
How come the combination of C(70,67) is 54,740?
 
Physics news on Phys.org
yakin said:
How come the combination of C(70,67) is 54,740?

The combination function is defined as:

$$C(n,r)={n \choose r}\equiv\frac{n!}{r!(n-r)!}$$

And so we have:

$${70 \choose 67}=\frac{70!}{67!(70-67)!}=\frac{70\cdot69\cdot68\cdot67!}{67!\cdot3!}=\frac{70\cdot69\cdot68}{3\cdot2}=35\cdot23\cdot68=54740$$
 
Hello, I'm joining this forum to ask two questions which have nagged me for some time. They both are presumed obvious, yet don't make sense to me. Nobody will explain their positions, which is...uh...aka science. I also have a thread for the other question. But this one involves probability, known as the Monty Hall Problem. Please see any number of YouTube videos on this for an explanation, I'll leave it to them to explain it. I question the predicate of all those who answer this...
I'm taking a look at intuitionistic propositional logic (IPL). Basically it exclude Double Negation Elimination (DNE) from the set of axiom schemas replacing it with Ex falso quodlibet: ⊥ → p for any proposition p (including both atomic and composite propositions). In IPL, for instance, the Law of Excluded Middle (LEM) p ∨ ¬p is no longer a theorem. My question: aside from the logic formal perspective, is IPL supposed to model/address some specific "kind of world" ? Thanks.
I was reading a Bachelor thesis on Peano Arithmetic (PA). PA has the following axioms (not including the induction schema): $$\begin{align} & (A1) ~~~~ \forall x \neg (x + 1 = 0) \nonumber \\ & (A2) ~~~~ \forall xy (x + 1 =y + 1 \to x = y) \nonumber \\ & (A3) ~~~~ \forall x (x + 0 = x) \nonumber \\ & (A4) ~~~~ \forall xy (x + (y +1) = (x + y ) + 1) \nonumber \\ & (A5) ~~~~ \forall x (x \cdot 0 = 0) \nonumber \\ & (A6) ~~~~ \forall xy (x \cdot (y + 1) = (x \cdot y) + x) \nonumber...

Similar threads

Replies
2
Views
2K
Replies
6
Views
2K
Replies
5
Views
2K
Replies
14
Views
2K
Replies
18
Views
3K
Replies
8
Views
2K
Back
Top