Vietnam is 3 times larger than Cuba.
Area: 110,860 km2 World Factbook
Population: 11,047,251 (July 2014) World Factbook
Cuba, officially the Republic of Cuba, is an island country in the Caribbean. The nation of Cuba comprises the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the capital of Cuba and its largest city. The second largest city is Santiago de Cuba. Wikipedia
Area: 331,210 km2 World Factbook
Population: 93,421,835 (July 2014) World Factbook
Vietnam, officially the Socialist Republic of Vietnam, is the easternmost country on the Indochina Peninsula in Southeast Asia. With an estimated 90.0 million inhabitants as of 2013, it is the world's 13th-most-populous country, and the eighth-most-populous Asian country. Wikipedia