Can you help with a maths question please?

Jambo · 24 Mar 2013 at 01:10

I think this should be quite easy but it is confusing me.

If from 100 numbers 1-100 you could pick 14, how many possible combinations is there? Repeat numbers are allowed.

Impy77 · 24 Mar 2013 at 01:13

Repeats allowed so it's 100 to the power 14.
100 ways for the 1st x 100 ways for the second choice x... Etc

Mason- · 24 Mar 2013 at 01:14

Impy77 said:
Repeats allowed so it's 100 to the power 14.
100 ways for the 1st x 100 ways for the second choice x... Etc

yeah 10 x 10^27 I think?

Randomface74 · 24 Mar 2013 at 01:45

http://www.wolframalpha.com/input/?i=100^14

Reaper 392 · 24 Mar 2013 at 01:57

when you say repeat numbers are allowed, are you considering that the choice (1, 1, 2, 2) is the same as or different to the choice (2, 2, 1, 1). Numbers have been repeated but they make the same set of numbers, just in a different order. If you consider those different choices then it is 100^14 as everyone else said. If you consider those two choices to be the same then it will be a lot more difficult to work out (and not something i feel like doing at 2am

)

Jambo · 24 Mar 2013 at 03:16

Reaper 392 said:
when you say repeat numbers are allowed, are you considering that the choice (1, 1, 2, 2) is the same as or different to the choice (2, 2, 1, 1). Numbers have been repeated but they make the same set of numbers, just in a different order. If you consider those different choices then it is 100^14 as everyone else said. If you consider those two choices to be the same then it will be a lot more difficult to work out (and not something i feel like doing at 2am )

Yeah they are different choices.

Thanks for the help everyone. Insane number and learned a new word in octillion!

Illgresi · 24 Mar 2013 at 04:38

Thought I'd through this in; It's tangential <--- also mathematical...

√-1 2^3 Σ π

Impy77 · 24 Mar 2013 at 07:28

Illgresi said:
Thought I'd through this in; It's tangential <--- also mathematical...

√-1 2^3 Σ π

i eight the sum of pi.... Or I ate all the pie?

estebanrey · 24 Mar 2013 at 08:20

Jambo said:
If from 100 numbers 1-100 you could pick 14, how many possible combinations is there? Repeat numbers are allowed.

Be careful with your wording, when you say 'combination' it means 1,2,3 & 3,2,1 count as being the same. If you want them to count as two of the total then you want to ask how many 'permutations' there are.

Anyway....

The number of COMBINATIONS for picking 14 numbers from 1-100 with repeat numbers allowed is....

((100+14)-1)! / (14! * (100-1)!) = 274,236,389,824,985,000

The number of PERMUTATIONS for picking 14 numbers from 1-100 with repeat numbers allowed is....

100^14 = 10,000,000,000,000,000,000,000,000,000

http://www.mathsisfun.com/combinatorics/combinations-permutations-calculator.html