I'm struggling with this problem for a while now, and I just can't figure it out.

Prove: Let $\displaystyle n_1, n_2, . . . , n_t \in N^+$

. If $\displaystyle n_1 + n_2 + . . . + n_t-t + 1$ Objects are laid in t

Pigeonholes then there's at least one $\displaystyle i \in \{1, . . ., t\}$

so that the i-th pigeonhole has at least $\displaystyle n_i$ objects

in it