Re: Combination Lock Problem

Re: Combination Lock Problem

Re: Combination Lock Problem

You could use the fundamental counting rule:

a) 30·30·30 = 27000

b) 30·29·28 = 24360

Re: Combination Lock Problem

Ah yea I saw that.

Had another question, similar to the one above.

I have 6 people, how many different ways can I seat the 6 people in six seats?

Would that just be a 2^{6}=32?

Or is this a 6! = 720?

Re: Combination Lock Problem

Using the fundamental counting rule, how many choices do you have for the first seat, second seat, and so on?

Re: Combination Lock Problem

ah ok got it. I thought it would be 6!, but it just seemed too big for six numbers. Never really thought about it I guess!

Re: Combination Lock Problem

Yes 6! is correct. There are n! ways to order n objects.

Re: Combination Lock Problem

I can use this same principle with say letters too, e.g. THEORY arranged in any order would be

6! = 720.

Then how about it I needed T and H to stay together, but could switch order, e.g. TH and HT are ok. Could I just say...

1.TH or HT

2.E

3.O

4.R

5.Y

Then say 5! = 120, but as TH can also be HT, double the result to give me the answer? so 240 possible orders.

Re: Combination Lock Problem

Re: Combination Lock Problem

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Re: Combination Lock Problem

Hey, I do appreciate those who click that thanks button, not just for my posts, but for anyone who gives a helpful reply! :)