Question 41121
Last digit can be any number chosen from 0 through 9. 
So there are 10 possibile values for the last digit.
In a similar way there can are 10 possible values of each of the 2nd, 3rd and 4th digit.
So the last 4 digits can be chosen in {{{10*10*10*10}}} = {{{10^4}}} ways.
The first digit can neither be 1 nor be 0.
So its value has to be chosen from numbers 2 through 9 i.e. from 8 numbers.
So the number of five digit numbers that can be formed with given constriction are {{{8*10^4}}} = 80000.