请问老师能解释下这是哪个知识点吗？为什么要加0.2，过程的逻辑是？

问题如下：

1. If Vander expects an 8 percent pretax return and capital gains are taxed at 20 percent, what is her accrual equivalent return over that time period?

选项：

6.40%.

6.78%.

4.60%.

解释：

B  is correct.

FV_cg =€400,000[(1 + r)ⁿ(1–t_cg) + t_cg]

=€400,000[(1 + 0.08)¹⁰(1–0.20) + 0.20]

=€770,856

Solving for the rate set equates €770,856 with its present value of €400,000

€770,856 =€400,000(1 + R_AE)¹⁰

R_AE = 0.0678 or 6.78 percent