How many license plates can be made which have the form ##LLL?
1,757,600
175,600
3,840,500
2,947,000

Question

How many license plates can be made which have the form ##LLL? 
      1,757,600
      175,600
      3,840,500 
      2,947,000

anonymous · Answer

Using fundamental principle of counting:

a. if repetitions are allowed:

N = 10 * 10 * 26 * 26 * 26 (10 digits, 26 letters)

N = 1,757,600

b. if repetitions are not allowed:

N = 10 * 9 * 26 * 25 * 24 (deduct 1 for every used character)

N = 1,404,000

i have answered in yahoo..
so never mind thats the same...