Question: 2018 Fall Midterm - 6
Let $S$ be a subset of the set $\{1,2,3,\dots,50\}$.
What is the minimum size of this subset $S$, such that there must be at least two elements in $S$ whose sum is equal to 51?
What is the minimum size of this subset $S$, such that there must be at least two elements in $S$ whose sum is equal to 51?
(a)
27
(b)
28
(c)
26
(d)
25