Mathematics Problem of the Week

Fall 2004

POW 9: Pushin’ 15

Let Y be a number with less than 30 digits that begins with 15 followed by a sequence of digits, i.e. 15a₁a₂…a_k. By multiplying Y by 5 we simply move all of the digits two places to the left to get the sequence of digits followed by 15, i.e. 5Y = a₁a₂…a_k15.

Find Y

Due Friday, Nov 5^th at Noon.

Solutions should be submitted to Dr. Maegan Bos’ mailbox in the Math office or sent via e-mail to mbos@stlawu.edu

Presentation counts! The prize-winning entry will be selected from all correct submissions, based on the clarity, creativity and elegance of the solution.

Look for the SLU POW on the Web at http://it.stlawu.edu/~math/activities/