Question: 2019 Winter Midterm - 6
Let $n \geq 1$ be an integer. A group of $n$ students write an exam. Each student receives a grade,
which is an element of the set $\{A, B, C, D, F\}$.
What is the minimum value for $n$, such that there must be at least four students who receive the same grade?
What is the minimum value for $n$, such that there must be at least four students who receive the same grade?
(a)
14
(b)
15
(c)
16
(d)
17