Question 962523
An office building has 7 doors. Four doors are only entrances to the building and two doors are only exits from the building. In how many different ways can someone enter and exit the building?
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Entries: 4 doors
Exits::: 2 doors
variable: 1 door
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Entry ways:: 5 ways
Exit ways::: 3 ways
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Total different ways to enter and leave::  5*3 = 15 ways
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Cheers,
Stan H.
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