Maths Olympiad Prep

Track / Stage 4 / 333 of 340 #593 of 1964

Problem 593

AMC 12 late, AIME early
Number theory Difficulty 5.0 Find the answer

5. (3 points) Three-digit even numbers A,B,C,D,EA, B, C, D, E satisfy A<B<C<D<EA<B<C<D<E. If A+B+C+D+E=4306A+B+C+D+E=4306, then AA is the smallest. \qquad

A number or a short expression. Spacing, $ signs and \frac vs / are all fine.

Official solution

【Solution】Solution: The largest three-digit even number is 998,
To satisfy AA being the smallest and A<B<C<D<EA<B<C<D<E, then EE is at most 998, DD is at most 996, CC is at most 994, and BB is at most 992,
4306(998+996+994+992)=43063980=326, \begin{array}{l} 4306-(998+996+994+992) \\ =4306-3980 \\ =326, \end{array}

Therefore, AA is at least 326. The answer is: 326.

Source: NuminaMath-1.5, licensed Apache-2.0. Statement and solution reproduced as published; topic, difficulty and ordering added by this site.