what is the sum of all 3 digit integers formed using the digits 34 and 5 ( repetition is allowed ) Options
A) 11982  B) 11984  C) 11985  D) 11988  E) 11986

Rationale: n = 3 * 3 * 3 = 27 = ( 555 + 333 ) / 2 = 444 sum = number of integers x average value n * = 27 * 444 = 11988 answer = d
Answer: D