问题如下：
Jack has $100,000 stocks and $100,000 bonds. The $100,000 stocks are in the taxable account and the $100,000 bonds are in the tax-deferred 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 Jack’s investment after 15 years?
选项：
A. $319,295
B. $327,765
C. $333,876
解释：
B is correct.
考点：Types of investment accounts
解析: 我们先算得放在交税账户中的股票投资在15年后的终值，注意到题目第三条中有说在交税账户中的股票收益全部看作递延的资本所得进行处理，所以
接着我们继续算得放在递延账户中的债券投资在15年后的终值。
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
218,707 + 109,058 = 327,765
老师请问，100,000{(1+0.06)^15−[(1+0.06)^15−1]×15%}中的 [(1+0.06)^15−1]*15%是指capital gain 的增值部分再乘以税率，是这样理解吗？
