Problem
COM-B1-M05-P005 Sum \(11\)
#5
★☆☆☆☆ Level 1 of 5
From \(1,\ldots,10\), \(6\) numbers are chosen. Prove that two chosen numbers have sum \(11\).
Split the numbers into \(5\) pairs with sum \(11\).
Pairs: \((1,10),(2,9),(3,8),(4,7),(5,6)\). Six numbers are chosen and there are five pairs, so one pair is fully chosen. Its sum is \(11\).
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