These four entrepreneurs from Africa are all worth billions of dollars. What they have in common is their commitment to succeed, determination, positive attitudes, and an impeccable work ethic. Whether you're starting out in your career and need motivation or you're a senior executive intrigued by these billionaires and how they made it big, we could all learn a few things from these business moguls: Aliko Dangote Net Worth: $21.6 billion Country of Origin: Kano, Nigeria As of last month, the Nigerian-born billionaire became the 23rd richest person in the world and the richest man on the African continent. Dangote is now on track to become the world's richest black man. The business mogul and industrialist started out by opening up a small trading company in 1977. The Dangote Group now operates globally and handles food processing, cement manufacturing, and freight. The company is a key supplier to soft drink companies and breweries internationally, and in Nigeria it is responsible for supplying to 70% of the market. With more than 11,000 employees, it is the largest industrial corporation in all of West Africa. In 2014, he donated 150 million naira ($1 million) to the Nigerian government to help prevent the spread of Ebola. [RELATED: Export Solutions for African American Entrepreneurs Interested in Africa] Mike Adenuga Net Worth: $4.6 billion Country of Origin: Ibadan, Nigeria Mike Adenuga is Nigeria's second- richest man. The self-made entrepreneur owns Nigeria's Globacom, which controls the second-largest telecom operator. The business mogul also has stakes in the Equatorial Trust Bank. In 1990, his company ConOil became the first oil company ever to discover oil in the constricted waters of Southwestern Ondo State. He was named African Entrepreneur of the Year at the African Telecoms Awards in 2007, and the following year launched Globacom, also known as Glo, which grew rapidly. Adenuga also became Grand Commander of the Order of Nigeria in 2012. Folorunsho Alakija Net Worth: $2.5 billion Country of Origin: Lagos, Nigeria Alakija works in various industries across fashion, printing, and oil. She was ranked the richest woman in Nigeria and listed as the 96th most powerful woman in the world by Forbes in 2014. At the age of 7, Alakija traveled to the UK to go to school; she returned to Nigeria for high school. After graduating from college in Lagos, she began her career as an executive secretary. Soon after, she established her own tailoring company, Supreme Stitches, which became an instant success and garnered national recognition within several years. She became national president of The Fashion Designers Association of Nigeria and promoted culture though her clothing. She also earned her oil prospecting license and entered into a joint agreement with Star Deep Water Petroleum Ltd. in 1996. Last year, the business magnate was appointed vice chairman of the National Heritage Council and Endowment for the Arts by the Nigerian federal government. Patrice Motsepe Net Worth: $2.3 billion Country of Origin: Soweto, South Africa Patrice Motsepe is the executive chairman and founder of African Rainbow Minerals. The mining tycoon was named South Africa's richest man in 2012. After earning his bachelor's and a law degree, he became the first black partner in a South African law firm in 1994. Motsepe majored in mining and business law, and he soon developed a mining services company, where services would clean gold dust from inside mine shafts. The price of purchasing gold in 1997 was at an extreme low, so the entrepreneur quickly struck up several deals and purchased gold mines from AngloGold. In 1999 he joined two associates to form Greene and Partners Investments. The publicly traded firm processes chrome, platinum, copper, nickel, coal, iron, manganese, and gold. He was awarded with South Africa's Best Entrepreneur Award in 2002 and was named the 503rd richest person in the world according to Forbes World Billionaires List in 2008. He became chairman of Teal Exploration and Mining Inc. in 2005. He is South Africa's first black billionaire, and earlier this year he generously donated $1 million to fight the spread of the Ebola virus in West Africa.