Friday, July 1, 2011

My answer ...

This morning a bud pointed me to a question in an article discussing the "20 Craziest Job Interview Questions".
What is the smallest number divisible by 225 that consists of all 1's and 0's?
Despite a heavy workload, I set a mental background processor on the problem.  Quickly, I determined that the answer must be a multiple of 4 for there to be only 1's and 0's.  4 times 225 is 900.  Consequently, the problem revolves around the smallest number divisible by 9 that consists of all 1's and 0's.

Typically, I really stink at these problems.  But my interest was peaked so I created a spreadsheet with multiples of 9 and simply looked for a pattern.  After a couple cups of coffee, deep in the recess of this foggy brain I remembered something about multiples of 9 adding up to 9 or adding up to a multiple of 9.  

So since multiples of 9 must add up to a multiple of 9 and I know that the last two digits must be "00" I guessed "11111111100".  It turns out that 9 * 49382716 = 11111111100.

Needless to say, I would not have gotten the job.