'Seventy five' in the Bible

So Abram departed [in faithful obedience] as the Lord had directed him; and Lot [his nephew] left with him. Abram was seventy-five years old when he left Haran.

Then his wife Zeresh and all his friends said to him, “Have a gallows fifty cubits high made, and in the morning ask the king to have Mordecai hanged on it; then go joyfully to the banquet with the king.” And the advice pleased Haman, so he had the gallows made.