How many CEO's has Yahoo! had in the past 5 years, and what were their names?

According to Wikipedia there has been 6 ceos and 2 interim in the history of Yahoo. 4 of them in the last 5 years along with the 2 interim.

Marissa Mayer (2012-Present)

Ross Levinsohn Interim (2012)

Scott Thompson (2012)

Tim Morse Interim (2011-2012)

Carol Bartz (2009-2011)

Jerry Yang (2007-2009)

Terry Semel (2001-2007)

Timothy Koogle (1995-2001)

http://en.wikipedia.org/wiki/Yahoo#Chief_Executive...

edit: I I used Wikipedia as my original source in part because it also links to biographies of the ceos.

There was also an Associated Press article that was picked up by several newpapers on May 14, 2012

http://www.mercurynews.com/business/ci_20619517/ya...

Also this Associated Press article states Thompson as the forth ceo in the past 5 years http://www.siliconvalley.com/yahoo/ci_20619471/key... . I guess the numbers can very if you count Semel in the "past five years" (July 07-July 12 Semel is not in the numbers) and/or you count the interim in numbers. The answer becomes anywhere from 4 to 7.

A list of CEOs at Sunnyvale Internet company Yahoo (YHOO).

Tim Koogle -- 1995-May 2001. Began tenure shortly after Yahoo was incorporated in March 1995. Announced in March 2001 that he would step down after a replacement is found.

Terry Semel -- May 2001-June 2007. Hired from Warner Bros. Stepped down under shareholder pressure.

Jerry Yang -- June 2007-January 2009. Company co-founder and de facto CEO until Koogle started. Agrees to resign under pressure in November 2008, pending appointment of replacement.

Carol Bartz -- January 2009-September 2011. Hired from Autodesk, a design and engineering software company. Fired after failing to revive the company.

Tim Morse -- September 2011-January 2012. Interim CEO, retained chief financial officer role after Scott Thompson took over.

Scott Thompson -- January 2012-May 2012. Hired from eBay's (EBAY) PayPal. Left after disclosure that his official biography included a college degree he never received.

Ross Levinsohn -- May 2012. Named interim CEO. Joined Yahoo in November 2010 following a stint running Internet services at News Corp.

And now of course, Google’s Marissa Mayer Becomes Yahoo’s Chief

I seems that the Company culture at Yhoo is so imbedded that the CEO's can't break through.They need a strong person to clean house and get the company growing

Darn, I was late and I can't just repeat a correct answer for points. :-(

They have had a whole bunch of them (6 as CEO) and you can expect the new one to last until the next stockholders meeting, at least. But most likely until the next earnings report.