License Plate Combinations: Clarifying the Math

[Mark44]

The set used for license plates, of course. i.e.: 26, sans I, O and Q.

That was an additional assumption/restriction on your part, not one that was given in the problem statement, and one that likely would have led to an incorrect answer.

 

[Mark44]

While that's probably outside the scope of the question

Yes.

mentioning it, and providing a second solution - might net you bonus marks!

Or not...

But the problem does specify a context (license plates) - one in which a non-conventional letter set is specified.

No, there is no mention whatsoever in the problem statement (which I quoted several posts back) about any non-conventional letter sets or any restrictions other than three letters followed by three digits.

Since the original question has been answered to the OP's satisfaction, and further talk about reduced sets of letters is off-topic, I am closing this thread.

 

[haruspex]

Of course I can, here below;
View attachment 263365
I hope our answers are the same

You are double counting some of the numerics. E.g. you are counting 112 as an example of x12 and as an example of 1x2.

 

[requied]

You are double counting some of the numerics. E.g. you are counting 112 as an example of x12 and as an example of 1x2.

So the answer became 36.504

 

[haruspex]

So the answer became 36.504

Yes.

 

[requied]

Yes.

I guess there is no a similar application at letters order.

 

[haruspex]

I guess there is no a similar application at letters order.

Quite so, that was easier. Had you only been told there was at least one A then, depending on your approach, there would have been a risk of double counting.
(But in that specific case the easy way is 26³-25³.)