11 Mar '21 03:47>
How many 4 digit numbers contain not more that two different digits?
@venda saidThat is an excellent line of thought, actually. It just needs some refinement.
Once again,I have successfully arrived at the wrong answer!
I realised my mistake on the post I deleted.
However I still have the wrong answer according to the answer given by dogg.
I would appreciate if someone could explain(preferably in language a 5 yr old can understand)what is wrong with my logic:-
The first digit selected cannot be a zero, so the number of digits ava ...[text shortened]... his train of thought in your head it is difficult to dislodge.
Sorry for appearing to be so thick!!
@bigdoggproblem saidThanks for the explanation.Makes it a lot clearer
That is an excellent line of thought, actually. It just needs some refinement.
Let's call the four digits F, S, T, and H, respectively.
Case 1: F is not equal to S
As you said, there are 9 possible digits for F.
Combine that with another 9 possible digits for S.
T must equal F, or S, so there are 2 possible digits for T.
However, there are also two p ...[text shortened]... s for H. (either F, or T)
9*9*2 = 162 possibilities
Total: 324 + 90 + 162 = 576 possibilities.
@venda saidTruth be told, I wrote a program to solve, first. Figured out the math later, again using programming to help.
Thanks for the explanation.Makes it a lot clearer
Seems I am like the horse in the steeplechase that leads all the way and then stumbles and falls at the last hurdle!
@bigdoggproblem saidI can do most things with spreadsheets but I've never done any programming as such apart from the odd macro when I was at work.
Truth be told, I wrote a program to solve, first. Figured out the math later, again using programming to help.
@venda saidYou'd have to find the location where you downloaded it, and delete it from there, or find out where you installed it, and uninstall from there.
As an aside, I downloaded a script for my chromebook to do a task for me.
I found out later I didn't really need it but can I get rid of it?!!
@bigdoggproblem saidThanks.
You'd have to find the location where you downloaded it, and delete it from there, or find out where you installed it, and uninstall from there.
If you cannot find it, try googling "uninstall chromebook script".