Determine the sum of all 3-digit positive integers which contain at least one odd digit and at least one even digit. (For purposes of the problem, zero is an even digit.)
a. all 3-digit positive integers sum up to 494550.
b. only numbers excluded are 111,222, ...999, summing up to 4995.
с. (added after Ch correction): b was wrong ,there is a much longer list: 111,113, ... 662,664... 997,999 , summing up to 123775
Answer: 494,550-4995 = 485555 w r o n g !
corrected: 494550 - 123775 = 370775
rem: Zero is an even digit, even in this problem.
Edited on August 3, 2015, 10:39 am