Two ways to answer the question:
Method 1:
The biggest is 999999
The smallest is 100000
Since both are included, the number is 999999 - 100000 + 1 = 900000
Method 2:
The first digit is chosen from 1 to 9 - ie 9 options.
With each choice of the first, the second digit is chosen from 0 to 9 - ie 10 options.
With each choice of the first and second, the third digit is chosen from 0 to 9 - ie 10 options.
and so on till the sixth digit.
So total number of options = 9*10*10*10*10*10 = 900000.
11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111
There are 449999 such numbers.
There are 90,000 such numbers.
720 of them.
Six
There are 5760 such numbers.
There are 449999 such numbers.
There are 90,000 such numbers.
720 of them.
The number of six digit numbers that you can make from ten different digits ifrepetitions of same digit on the six digit number is allowed is 1 000 000 numbers(including number 000 000).If no repetitions of the the same digit are allowed then you have:10P6 = 10!/(10-6)! = 151 200 different six digit numbers(six digit permutations form 10 different digits).
1000... 0600-0699 1600-1699 and so on.
six
There are a handful of six digit numbers that have no numbers repeating. Some examples are 123456, 234567, 345678, 456789, 567012, 654321, 765432, 876543, and 987654.
There are 500000 such numbers.
899100 of them. Only 900 of the 900000 are palindromic.
100,000
Six
There are 12,500 of them and I am not going to list them. One of them is 200000.