How many possible three-digit passwords can be formed using digits 0 through 9 if no digits are repeated?
1 Answer
Jul 8, 2016
120 three - digit passwords can be formed
Explanation:
You have to find the combinations. The formula is -
#""_nC_r=(n!)/((n-r)!.r!)#
Where -
n - stands for total Number of items
r - stands for number of items chosen at a time.
In our case -
#n=10#
#r=3#
#""_10C_3=(10!)/((10-3)!3!)=(10xx9xx8xxcancel7!)/(cancel(7!)3xx2xx1)=10xx3xx4xx1=120#
