combination
A combination lock has 35 numbers on it. how many different 3-digit lock combinations are possible if no digit can be repeated

Question

combination 
A combination lock has 35 numbers on it. how many different 3-digit lock combinations are possible if no digit can be repeated

nnesha · Answer

the reason why i joined os  months ago ;-;^

nnesha · Answer

my first question was also about permutation and combination

jagr2713 · Answer

Oh we did that yesterday

nnesha · Answer

that question was easy

jagr2713 · Answer

Oh ok b.c i remember doing combination and permutation yesterday with someone.

I joined OS like 2yrs ago but they only count the days you log in so it says i only been here for 3months

nnesha · Answer

there is an error

amistre64 · Answer

35 numbers?  not sure what 35** notation means

nnesha · Answer

yea 35 numbers

thesmartone · Answer

35 numbers how?? If it's 3 digits then it can have a max of 10 for one digit, then 9 for the second digit, and 8 for the 3rd digit..

amistre64 · Answer

35 nordic runes maybe lol

nnesha · Answer

it's 35  on the paper   let me wear my glasses

nnesha · Answer

yeah 35 numbers

nnesha · Answer

answer is ) 39270

thesmartone · Answer

Well then we would use permutations.

thesmartone · Answer

$\sf 35p3$

nnesha · Answer

i did and i got 6545

thesmartone · Answer

$\sf\Large =\frac{35!}{(35-3)!}$

nnesha · Answer

wait yeah that's right

thesmartone · Answer

@Nnesha The question says a combination lock, so you did combinations. But we are actually supposed to use permutations to solve it.

nnesha · Answer

but why permutation? 
if i'm nt mistaken
permutation when order is important :D

thesmartone · Answer

Because you can not repeat the number, so order is important.

thesmartone · Answer

and thus why we use permutation. (And you are correct.)

nnesha · Answer

thanks $\large\color{green}{\rm smart!}$

thesmartone · Answer

Anytime $\sf\color{green}{Nnesha!}$ :)