All of the citizens of a country have a seven-character or eight-character national identification code that is created using the 26 letters of the alphabet and the 10 digits from 0 to 9. What is the maximum number of citizens who can be designated with these codes? Choose the correct option: A) 36^15 B) 35(36^7) C) 35(36^8) D) 37(36^7) E) 37(36^8)
The number of possible 7-digit codes is 36^7.   The number of possible 8-digit codes is 36^8.   The total sum is 36^7 + 36^8 = 36^7(1+36) = 37(36^7)   The answer is 37(36^7).
<result>D</result>
All of the citizens of a country have a seven-character or eight-character national identification code that is created using the 26 letters of the alphabet and the 10 digits from 0 to 9. What is the maximum number of citizens who can be designated with these codes?