iran-konkur 2019 Q149

iran-konkur · Other · konkur-riazi_1398_specialized_new-curriculum Not Maths
149. From the set of numbers $\{5, 8, 11, \ldots, 65, 68, 71\}$ which forms an arithmetic sequence, at least how many members must be selected so that we are certain that at least two numbers exist in this subset whose sum is $82$?
(1) $11$ (2) $12$ (3) $13$ (4) $14$
\textbf{149.} From the set of numbers $\{5, 8, 11, \ldots, 65, 68, 71\}$ which forms an arithmetic sequence, at least how many members must be selected so that we are certain that at least two numbers exist in this subset whose sum is $82$?

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(1) $11$ \hfill (2) $12$ \hfill (3) $13$ \hfill (4) $14$

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