SOLUTION: A combination lock is set up in the office. The keypad is set up with numbers 0-9 and you know the combination is a 4 digit combo. You also know that numbers are not repeated in th

Algebra ->  Permutations -> SOLUTION: A combination lock is set up in the office. The keypad is set up with numbers 0-9 and you know the combination is a 4 digit combo. You also know that numbers are not repeated in th      Log On


   

Question 482573: A combination lock is set up in the office. The keypad is set up with numbers 0-9 and you know the combination is a 4 digit combo. You also know that numbers are not repeated in the combination. How many different combinations of 4 can be created?


Found 2 solutions by caloy, tmwilliamlin168:
Answer by caloy(2) About Me  (Show Source):
You can put this solution on YOUR website!
number of combinations= 10 x 9 x 8 x 7
= 5040 ways

Answer by tmwilliamlin168(27) About Me  (Show Source):
You can put this solution on YOUR website!
You start of with 10 possible numbers for the first number (0~9)
One of them is used so the second number only has 9 possibilities
8 for the third, and 7 for the last
If you multiply the numbers it will be the number of possibilities
10*9*8*7=5040