Difference between revisions of "2017 AMC 10A Problems/Problem 10"
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~savannahsolver | ~savannahsolver | ||
| + | ==EASIEST and FASTEST SOLUTION,== | ||
| + | https://www.youtube.com/watch?v=7u4uE2Fh1NY&feature=youtu.be | ||
==See Also== | ==See Also== | ||
Latest revision as of 10:00, 19 August 2025
Problem
Joy has
thin rods, one each of every integer length from
cm through
cm. She places the rods with lengths
cm,
cm, and
cm on a table. She then wants to choose a fourth rod that she can put with these three to form a quadrilateral with positive area. How many of the remaining rods can she choose as the fourth rod?
Solution 1
The triangle inequality generalizes to all polygons, so
and
yields
. Now, we know that there are
numbers between
and
exclusive, but we must subtract
to account for the 2 lengths already used that are between those numbers, which gives
Video Solution
~savannahsolver
EASIEST and FASTEST SOLUTION,
https://www.youtube.com/watch?v=7u4uE2Fh1NY&feature=youtu.be
See Also
| 2017 AMC 10A (Problems • Answer Key • Resources) | ||
| Preceded by Problem 9 |
Followed by Problem 11 | |
| 1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 | ||
| All AMC 10 Problems and Solutions | ||
These problems are copyrighted © by the Mathematical Association of America, as part of the American Mathematics Competitions.