SOLUTION: Having some difficulty with this type of problem: Account numbers for Western Oil Company consist of five digits. If the first digit cannot be 0 or 1 how many account numbers ar

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Question 41121: Having some difficulty with this type of problem:
Account numbers for Western Oil Company consist of five digits. If the first digit cannot be 0 or 1 how many account numbers are possible?

Found 2 solutions by fractalier, psbhowmick:
Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
Well, since the first digit must begin with at least a 2, the numbers that are allowed are 20000 thru 99999, or 80000 account numbers possible...

Answer by psbhowmick(878) About Me  (Show Source):
You can put this solution on YOUR website!
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%2A10%2A10%2A10 = 10%5E4 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%2A10%5E4 = 80000.