Combination Calculation. Please Help.

[Maths Noob]

Hi there,

This is my first post, I'm useless at maths, but I want to get better.

I have 3 separate columns containing 7 music clips each, each column is playing 1 of the 7 clips at random simultaneously.

How do I calculate how many combinations can be played?

Is it 7 x 7 x 7 =7³ ?

That gives me 343, but that seems too small.

Is there some kind of random-variable-permutation principle I'm missing?

What about factoring in repeats?

Please help, my brain hurts!

Thanks in advance

Regards

Maths Noob

 

[Dr.Peterson]

You aren't useless; you got it right! You just don't have the right intuition -- and it takes a lot of experience to get that.

If you want to convince yourself that the answer is correct, try listing all the possibilities.

I'm not sure what it means for a column to play music, but I don't need to know! If the first can be A, B, C, D, E, F, or G, and the second can be H, I, J, K, L, M, or N, and the third can be O, P, Q, R, S, T, or U, then start with AHO, then AHP, and so on to GNU, and you should find you've listed 343 "words". (Or you could do it with A, B, C, D, E, F, or G for each of them: AAA, AAB, ..., GGG.)

Or think about numbers. How many 3-digit numbers are there? Each digit has ten choices; and from 000 to 999 there are 1000 numbers. So your answer has to be less than that!