Art of Problem Solving

2025 AMC 10A Problems/Problem 21: Difference between revisions

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(Problem goes here)
==Solution 1==
Let our subset be <imath>\{11,12,13,...,20\}.</imath> If we add any one element from the set <imath>\{1,2,3,...,10\},</imath> we will have to remove at least one element from our current subset. Hence, the size of our set cannot exceed <imath>\boxed{\text{(C) }10}.</imath>
~Tacos_are_yummy_1


==See also==
==See also==

Revision as of 12:58, 6 November 2025

(Problem goes here)

Solution 1

Let our subset be $\{11,12,13,...,20\}.$ If we add any one element from the set $\{1,2,3,...,10\},$ we will have to remove at least one element from our current subset. Hence, the size of our set cannot exceed $\boxed{\text{(C) }10}.$

~Tacos_are_yummy_1


See also

2025 AMC 10A (ProblemsAnswer KeyResources)
Preceded by
Problem 20
Followed by
Problem 22
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
2025 AMC 12A (ProblemsAnswer KeyResources)
Preceded by
Problem 17
Followed by
Problem 19
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 12 Problems and Solutions

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