Help with both if possible

3. How long, to the nearest year, will it take an investment in U.S. to double its value if the interest is compounded every six months? Please round the answer to the nearest year. Country U.S. Japan Canada Korea Australia Yield 5.3% 1.5% 5.2% 15.4% 6.0% A. 14 years B. 16 years C. 13 years D. 8 years E. 15 years 4. Find the logistic function f with the given properties. f(0) =1, fhas limiting value 20, and for small values of x, f is approximately exponential and grows by 50% with every increase of 1 in x. 20 A) f(x) = B) f(x) = C) f(x) = _20 1+1.5 x 1+19 1.5 x 1+2-* 20 20 D) f ( x ) = - E) f(x) = 1+19 2-x 1+1.5x