Burundi is 2.5 times larger than Gambia.
Area: 27,830 km2 World Factbook
Population: 10,395,931 (July 2014) World Factbook
Burundi, officially the Republic of Burundi, is a landlocked country in the African Great Lakes region of Southeast Africa, bordered by Rwanda to the north, Tanzania to the east and south and the Democratic Republic of the Congo to the west. It is also sometimes considered part of Central Africa. Wikipedia
Area: 11,295 km2 World Factbook
Population: 1,925,527 (July 2014) World Factbook
The Gambia is a country in West Africa. It is surrounded by Senegal, apart from a short strip of Atlantic coastline at its western end. It is the smallest country on mainland Africa. Wikipedia