Question 265262: All airplanes in the United States have identification letters that start with the letter N. Private planes have the letter N followed by four numbers followed by another letter. The letters I, O, and Z are never used. How many possible private aircraft identification numbers are there?
Answer by dabanfield(803)   (Show Source):
You can put this solution on YOUR website! All airplanes in the United States have identification letters that start with the letter N. Private planes have the letter N followed by four numbers followed by another letter. The letters I, O, and Z are never used. How many possible private aircraft identification numbers are there?
W ewill need to use the rule that says if one event can occur in n ways and another in m ways then the two events together can occur in m*n ways.
The second, third, fourth and fifth positions can each be chosen in 10 ways (0,1,2...9). The sixth position can be chosen from one of the 23 remaining letters of the alphabet.
So the number of ways to fill the last five positions is:
10*10*10*10*23 = 230,000
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