Difference between revisions of "2021 JMPSC Sprint Problems/Problem 5"

Line 10: Line 10:
  
 
-OofPirate
 
-OofPirate
 +
 +
 +
 +
==See also==
 +
#[[2021 JMPSC Sprint Problems|Other 2021 JMPSC Sprint Problems]]
 +
#[[2021 JMPSC Sprint Answer Key|2021 JMPSC Sprint Answer Key]]
 +
#[[JMPSC Problems and Solutions|All JMPSC Problems and Solutions]]
 +
{{JMPSC Notice}}

Revision as of 16:12, 11 July 2021

Problem

What two-digit even number has digits that sum to $17$?

Solution

There exists a $2$ digit even number that has digits that sum to $17$. Pertaining to the assumption that this operation is in base $10$, there exists only $10$ digits to be used, specifically only $5$ for the first digit. Only $8$ and $9$ may be used, as there isn't other pair of digits which sum to $17$

The only two numbers in which satisfy the fact that the digits sum to $17$ are $98$ and $89$. Yet, only $98$ works because it is the only one in which satisfies the condition that the number must be even.

Therefore, $\boxed{98}$ is the only two-digit even number that has digits that sum to $17$.

-OofPirate


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

Invalid username
Login to AoPS