Over time, compound interest at any rate will outperform simple interest. When the rates are nearly equal to start with, compound interest will be greater in very short order. Here, it takes less than 1 year for compound interest to give a larger account balance.
In 30 years, the simple interest will be
... I = P·r·t = 12,000·0.07·30 = 25,200
In 30 years, the compound interest will be
... I = P·(e^(rt) -1) = 12,000·(e^(.068·30) -1) ≈ 80,287.31
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6.8% compounded continuously results in more total interest