San Francisco, Dec 10 (IANS): College papers graded by Tesla CEO Elon Musk, when he worked as a teaching assistant at the University of Pennsylvania in 1995, have been sold for $7,753 (around Rs 5,87,099) in an auction.

According to Daily Mail, while pursuing his Economics and Physics degrees, Musk graded many papers, including those from the Management 231, 'Entrepreneurship: Implementation and Operations' class, taught by Professor Myles Bass.

The papers belonged to Brian Thomas, one of Bass's students, who, as an inside joke had included a phrase when referring to the circumstances in which a company needed an 'exit strategy'.

But Musk did not find the idiom appropriate, writing 'Graphic' over them, and deducting two points from Thomas' grade, the report said.

Before founding SpaceX and Tesla, and amassing a fortune of $277 billion that would make him the richest man in the world, Musk was a student and Teacher Assistant at University of Pennsylvania's famous Wharton School of Business.

Meanwhile, Thomas said "he found the papers when he was looking for school yearbooks in the garage with his son". He had kept them because of the fond memories he had from being in the class taught by Bass, who died in 2010.

Thomas then handed the papers to Boston's RR Auctions to be sold, the report said.