2021 JMPSC Sprint Problems/Problem 17

Revision as of 16:15, 11 July 2021 by Mathdreams (talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

Problem

What is the smallest positive multiple of $1003$ that has no zeros in its decimal representation?

Solution

Notice that $1003 \cdot n = 1000n + 3n$. Since $1000n$ always has $3$ zeros after it, we have to make sure $3n$ has $3$ nonzero digits, so that the last 3 digits of the number $1003n$ doesn't contain a $0$. We also need to make sure that $n$ has no zeros in its own decimal representation so that $1000n$ doesn't have any zeros other than the last $3$ digits. The smallest number $n$ that satisfies the above is $\frac{111}{3}=37$, so the answer is $1003 \cdot 37 = \boxed{37111}$.

~Mathdreams

~edited by tigerzhang

See also

  1. Other 2021 JMPSC Sprint Problems
  2. 2021 JMPSC Sprint Answer Key
  3. All JMPSC Problems and Solutions

The problems on this page are copyrighted by the Junior Mathematicians' Problem Solving Competition. JMPSC.png