How many 5 digit number are there in all?

Answer 1

89999 5-digit numbers are there in all...

That is the numbers from 10000 to 99999...

Wrong. There are 90000 five digit numbers in all.

When you start to count you count from 10001 to 99999which is 89999 numbers. To that you add the one number 10000.

89999+1=90000

Answer 2

The first digit cannot be "0", if it is it won't make a 5 digit number

So first digit can be 1,2,3,4,5,6,7,8, or 9

Second through fifth digit can be 0,1,2,3,4,5,6,7,8, or 9

So total number of 5 digit number is 9 x 10 x 10 x 10 x 10 = 90000

Answer 3

90000