39. the answer is...

nine (9)

The Constitution does not establish the number of justices on the Supreme Court. In the past, there have been as many as 10 and as few as six justices. Now, there are nine justices on the Supreme Court: eight associate justices and one chief justice. The Constitution gives the president the power to nominate justices to the Supreme Court. The nominee must then be confirmed by the Senate. Justices serve on the court for life or until they retire. For more information on the U.S. Supreme Court, go to http://www.supremecourtus.gov.