The set X consists of the following terms: {4,44,444,4444,.....}, where the nth term has n 4's in it for example 10th term is 4444444444. What is the hundreds digit of the sum of the first 55 terms of set X?
Pick:
A) 1
B) 3
C) 5
D) 7
E) 9
55*4 + 54*40 + 53*400 = 220 + 2160 + 21200= 
<gadget id="calculator">220 + 2160 + 21200</gadget>
<output>23_580</output>
23580   The hundreds digit is 5.   The answer is 5.
<result>C</result>
The set X consists of the following terms: {4,44,444,4444,.....}, where the nth term has n 4's in it for example 10th term is 4444444444. What is the hundreds digit of the sum of the first 55 terms of set X?