508. How long did Jehoash reign?

40 years

In the seventh year of Jehu Jehoash began to reign; and forty years reigned he in Jerusalem. 2 Kings 12:1

16 years

In the thirty and seventh year of Joash king of Judah began Jehoash the son of Jehoahaz to reign over Israel in Samaria, and reigned sixteen years. 2 Kings 13:10