TDA账户的计算不懂

问题如下：

Tom has $100,000 stocks and $100,000 bonds. The $100,000 stocks are in the tax-deferred account and the $100,000 bonds are in the taxable account. We assume that:

1. The stock will provide 6% annually return.

2. The bond will provide 3% annually return.

3. Stock returns in taxable account will be taxed as whole deferred capital gains at a 15% percent rate. Interest income in taxable account is at 30 percent for each year.

4. Contributions in Tax-deferred account are not taxed, but withdrawals from this account will be taxed at 30 percent.

5. Cost basis is equal to 1

Calculate the post-tax value of Tom’s investment after 15 years.

选项：

$304,339

$369,076

$209,876

解释：

A is correct.

考点：Types of investment accounts

解析，我们先算得放在交税账户中的债券投资在15年后的终值。

$FV_{taxble}=100,000{\lbrack{1+0.03(1-0.3)}\rbrack}^{15}=136,580$

接着我们继续算得放在递延账户中的股票投资在15年后的终值。

$FV_{TDA}=100,000{(1+0.06)}^{15}{(1-0.3)}=167,759$

最后我们把两个资产账户的终值相加，便得到Tom15年后投资的总市值，即

136580 + 167759 = 304,339