A century has 100 years. Therefore, there are ten decades in a century. (100 divided by 10 = 10). A generation is considered 20 years. Silver wedding anniversary = 25 years. Golden wedding anniversary = 50 years. A decade is ten years. A century has 100 years. Therefore, there are ten decades in a century. (100 divided by 10 = 10).<br />A generation is considered 20 years.<br />Silver wedding anniversary = 25 years<br />Golden wedding anniversary = 50 years.