All of the citizens of a country have a three-character or four-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?
Pick:  A) 36^7  B) 37(36^3)  C) 35(36^4)  D) 35(36^3)  E) 37(36^4)
The number of possible 3-digit codes is 36^3.   The number of possible 4-digit codes is 36^4.   The total sum is 36^3 + 36^4 = 36^3(1+36) = 37(36^3)   The answer is 37(36^3).
<result>B</result>
All of the citizens of a country have a three-character or four-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?