Talk:Positive decimal integers with the digit 1 occurring exactly twice
(Redirected from Talk:Numbers in which the digit 1 occurs twice)
number of ways to place two ones in three slots
This is the number of ways to place two ones in three slots, which is three, times the number of ways to place 0,2-9 in the remaining slot, which is nine. So at least twenty seven is the correct answer. Surely somewhere this task is already covered.--Nigel Galloway (talk) 17:00, 8 July 2021 (UTC)
- This task can have my vote for deletion as well. --Pete Lomax (talk) 03:58, 9 July 2021 (UTC)
- It is a variant of the task Permutations_with_some_identical_elements.--Nigel Galloway (talk) 15:57, 10 July 2021 (UTC)
suggest a task rename
I suggest that this (draft) task be renamed to reflect:
- that positive integers be specified instead of numbers.
- that the number one be found in the number be changed to the digit one be found in ...
- indicate that the integers be expressed in base ten.
- specify that exactly two one digits be found.
The number 1211 does have two 1 digits in it. It also has a 1 digit in it.
I've already modified the (draft) task's requirements (as everyone appears to have already assumed positive base ten numbers). -- Gerard Schildberger (talk) 23:27, 8 July 2021 (UTC)