Question

What is the 1000th positive integer with an odd number of digits?

Answer 1

try to counting such numbers to get the 1000th
start with positive integers with 1 number of digits --> 9
positive integers with 3 number of digits --> 999-99=900
...

Answer 2

See positive odd integers are : 1 3 5 7 ..
So, it becomes an Arithmetic Progression of which we have to find the nth term ie 1000th..

So here n = 1000

a = 1 and d = 3 - 1 = 2

So,
\[t_n = a + (n - 1)d\]

Put a, d and n value to find tn..

Answer 3

I think I am somewhat wrong in that..
What you think @mukushla ??

Answer 4

@waterineyes 'with an odd number of "digits" '

Answer 5

like this
1,2,3,4,5,6,7,8,9,100,101,103,...,999,10000,10001,...

Answer 6

Oh sorry there is a big mistake in understanding the question..
So, the number of digits in a number must be 1, 3, 5 etc etc..

Answer 7

so we looking at odd numbers so that we are looking for the 1000th number in the sequence 0,...,9,100,....,999,10000,...,99999,....
now from 0 to 9 we have 10 digits, so that 9 is the 10th number. from 100 to 999 we have 900 numbers, so that 999 is the 910th number. 10000 is the 911th number,10001 is 912th number,...., 10089 is the 1000th number.