Industrialist Aliko Dangote is known as a mild-mannered cement tycoon who often drives himself to business meetings. How did he become the world’s richest black person? Dangote rapidly dominated Nigeria’s cement, sugar, flour and fertiliser markets. He says his mission is to make Nigeria’s economy self-reliant, without requiring Western investment or imports. BBC business editor Simon Jack and journalist Zing Tsjeng look back on Dangote’s life - from a childhood selling sweets in the playground to becoming a watchword for success in Nigeria. Then they decide if they think he’s good, bad, or just another billionaire.