What is the sum of all possible 3-digit numbers that can be constructed using the digits 1, 2, and 4 if each digit can be used only once in each number?  Pick:
A) 1210 B) 1221 C) 1332 D) 1443 E) 1554

Rationale: there are 6 possible arrangements of the three numbers . then each number will be in the hundreds , tens , and ones place two times each . the sum is 2 ( 111 ) + 2 ( 222 ) + 2 ( 444 ) = 1554 the answer is e .
Answer: E