A small combination lock on a suitcase has 3 wheels, each labeled with the 10 digits 0 to 9.
How many 3 digit combinations are possible if no digit repeated? If digits can be repeated? If successive digits must be different?
Solution:-
a. The number of different 3 digit combinations possible if no digit is repeated is 720.
b. The number of different 3 digit combinations possible if digits can be repeated is 1000.
c. The number of different 3 digit combination possible if successive digit must be different is 810.