Meet the billionaires who dropped out of college (or Ph.D.)

RALPH LAUREN, 80. Net worth: $5.8 billion. He only finished two years of college. Forbes described him as "the man who made American fashion cool"

JAN KOUM, 44. Net worth: $10 billion. He dropped out of San Jose State University, worked at Yahoo for nine years before founding WhatsApp.

MARK ZUCKERBERG, 36. Net worth: $66 billion. Left Harvard after his sophomore year to focus on Facebook. Zuckerberg founded the social network to help fellow students learn the names of the people in their classes. .

TED TURNER, 81. Net worth: $2.2 billion. He was expelled from Brown University. Turner turned out to be a pioneering American media proprietor, producer, and philanthropist. As a businessman, he is known as founder of the Cable News Network (CNN), the first 24-hour cable news channel.

TY WARNER, 75. Net worth: $2.6 billion. Ty Warner, known as the creator of Beanie Babies, dropped out of Kalamazoo College in 1962 because he reportedly couldn't afford it.

David Geffen, 77. Net worth: $8.4 billion. He dropped out of the University of Texas at Austin, worked as a talent agent at William Morris prior to founding DreamWorks.

MICHAEL S. DELL, 55. Net wroth: $30.6 billion. Dell spent his spare time as a student upgrading PCs. Then he sold them from his dorm room. He made $180,000 in his first month of business the summer after his freshman year and never went back to school.

LARRY ELLISON, 75. Net worth $63. He dropped out of college twice. After high school, enrolled in the University of Illinois at Urbana-Champaign, but dropped out during his sophomore year after his adoptive mother died. He later completed one semester at the University of Chicago.

Bill Gates, 64. Net worth: $102 billion. Gates is considered "Harvard's most successful dropout." He left the university during his sophomore year in 1975 and founded Microsoft.

STEVE JOBS (b.1955, d. 2011); Net worth: $10.2 billion. Jobs dropped out of Reed College to become the father of all things Apple. Before he left Reed, he took a calligraphy class that later inspired him to include a wide range of fonts (vs. one standard text) on the first Macs. That's how he endeared artists to the Mac. Jobs is said to have made artists, instead of geeks, love computers too.

ELON MUSK, 49. Net worth: $70.6 billion. Strictly speaking, Elon is not a college dropout. He did receive a degree in Economics from the University of Pennsylvania Wharton School and Physics from the College of Arts and Sciences. He then began a Ph.D. in applied physics at Stanford University, but dropped out in two days to start his first company called Zip2, which he created in 1995 to provide business directories and maps to media companies and local e-commerce merchants (bought by Compaq for $340 million). Later, Musk co-founded X.com, which was merged with PayPal, then sold it to eBay for $1.5 in stock, of which he received $165 million. With that money, the founded Tesla and SpaceX, among others.