A score equals 20. Consequently, “three score and five years” means 65 years.
The northern kingdom of Israel was captured by Assyria in 722 B.C., and many of the inhabitants (known today as the lost tribes of Israel) were carried away. Captives from other lands were relocated in the area and eventually intermarried with the remaining Israelites and became known as the Samaritans. “Ephraim be broken” happened as prophesied; within the span of 65 years, Ephraim was no more.