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The formula used with continuous compounding interest is: A = Pe^rt we are given A, P and r: 2000 = 1000e^0.04t divide both sides by 1000: 2 = e^0.04t take Napierian log of both sides: ln2 = 0.04t divide both sides by 0.04: t = ln2/0.04 ~ 17.33 years or 17years 4 months

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