Answer:
A. approximately 56 years
Step-by-step explanation:
Giving that
Annual percentage growth rate = 2.5%
Using rule of 70
Years to double = 70 ÷ 2.5
= 28 years
Therefore, years to quadruple from original GDP
= 28 × 2
= 56 years
Therefore it will take 56 years for US GDP to reach 200,000 from 50,000 at annual rate of 2.5