Answer:
10.4%
Explanation:
In macroeconomics class we are told that if an economy grows by 10%, it will take them 7 years to double its size.
The answer is not exactly 10%, but it's pretty close:
(1 + x%)⁷ = 2
1 + x% = ⁷√2
1 + x% = 1.104
x% = 1.104 -1 = 0.104 or 10.4%
We can check the answer: 1.104⁷ = 2