A decade is 10 years so eight and a half decades is 85 years.
Four score years, or eight decades.
45 years
25 years
440 years
A decade is ten years. So, four decades is forty years.
Forty
Forty years is equal to four decades. This is because each decade represents a period of 10 years.
from 1945 to 1991, so four and a half.
There are 5 decades in half a century.
four and a half.
There are 3.5 decades in 35 years