Zambia is 67 times larger than Gambia.
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
Area: 752,618 km2 World Factbook
Population: 14,638,505 (July 2014) World Factbook
The Republic of Zambia is a landlocked country in Southern Africa, neighboring the Democratic Republic of the Congo to the north, Tanzania to the north-east, Malawi to the east, Mozambique, Zimbabwe, Botswana and Namibia to the south, and Angola to the west. Wikipedia