SOLUTION: In a hotel in Hong Kong, a room key is a card. The card has positions for holes that form a 4 by 6 arrays. Each position in the array is either punched with a hole or left blank. H

Algebra ->  Permutations -> SOLUTION: In a hotel in Hong Kong, a room key is a card. The card has positions for holes that form a 4 by 6 arrays. Each position in the array is either punched with a hole or left blank. H      Log On


   



Question 960030: In a hotel in Hong Kong, a room key is a card. The card has positions for holes that form a 4 by 6 arrays. Each position in the array is either punched with a hole or left blank. How many different keys are possible?
The answer is 16777216, but I am not sure what are the steps to solving this.

Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

given:
4 by 6 arrays=>4%2A6=24
punched or not = 2 choices
total_+combinations+=+2%5E24=+16777216