153. In how many ways can 9 identical books be placed in 5 shelves such that at least one book is placed on each shelf? (1) $35$ (2) $42$ (3) $56$ (4) $70$
\textbf{153.} In how many ways can 9 identical books be placed in 5 shelves such that at least one book is placed on each shelf?
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(1) $35$ \hfill (2) $42$ \hfill (3) $56$ \hfill (4) $70$
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