问一道题：NO.PZ2018091705000021 [ CFA III ]

Allen is investment manager, who recently recruitea new customer, Polly. Polly investe$100,000 in asset for 20 years thpromises to offer annuinterest of 8% before twithout any capitgain. But the investment account is expecteto taxe15% annually. Calculate the post-treturn on the investment after 20 years later. $383,121.09 $372,756.35 $339,092.56 B is correct. 考点AccruTaxation 解析根据Accrutaxes的公式，可得 FVAT=PV[1+R(1−T)]N=100,000×(1+8%(1−15%))20=372,756.35FV_{AT}=PV{\lbrack1+R(1-T)\rbrack}^N=100,000\times{(1+8\%{(1-15\%)})}^{20}=372,756.35FVAT​=PV[1+R(1−T)]N=100,000×(1+8%(1−15%))20=372,756.35 老师，这一题是问Return，不是问FV。 为啥结果不用减去本金？

Be请问，题目说对投资账户征税，为什么不是wealth base 呢，谢谢

Allen is investment manager, who recently recruitea new customer, Polly. Polly investe$100,000 in asset for 20 years thpromises to offer annuinterest of 8% before twithout any capitgain. But the investment account is expecteto taxe15% annually. Calculate the post-treturn on the investment after 20 years later. $383,121.09 $372,756.35 $339,092.56 B is correct. 考点AccruTaxation 解析根据Accrutaxes的公式，可得 FVAT=PV[1+R(1−T)]N=100,000×(1+8%(1−15%))20=372,756.35FV_{AT}=PV{\lbrack1+R(1-T)\rbrack}^N=100,000\times{(1+8\%{(1-15\%)})}^{20}=372,756.35FVAT​=PV[1+R(1−T)]N=100,000×(1+8%(1−15%))20=372,756.35  the investment account is expecteto taxe15% annually.为什么不是account整体征税，为什么只有增值部分征税？

按计算器结果是320713.5根据公式按