The Teivah was 50 cubits wide. ([Bereishis 6:15][1])

A Purim Torah - Where does Noach come into the Megillah? Haman went to look for a tree that's 50 amos high... he searched and searched until he came to Noach's Teivah


  [1]: http://www.mechon-mamre.org/p/pt/pt0106.htm#15