66) What is the rate on an investment that triples $4848 in 3 years? Assume interest is compounded monthly A) 46 5% B) 31.0% C) 37 2% D) 24 8% 67) How long will it take a sample of radioactive substance to decay to half of its original amount, if it decays according to the function A(t) = 800e-207t, where t is the time in years? Round your answer to the nearest hundredth year D) 165.60 years A) 35.64 years C) 3.35 years B) 32.29 years 68) An artifact is discovered at a certain site. If it has 52% of the carbon-14 it originally contained, what is the approximate age of the artifact to the nearest year? (carbon-14 decays at the rate of 0.0125% annually.) B) 3840 years A) 5231 years D) 2272 years C) 4160 years 69) How long will it take for $9800 to grow to $14,500 at an interest rate of 6.1% if the interest is D) 0.24 compounded continuously? Round the number of years to the nearest hundredth. C) 0.64 B) 642 24 A) 6 42