Answer:
True the trustee does not have access to the gain on the investment.
Step-by-step explanation:
All increase in trust is for the benefit of the trust.
Ideally, the trustee should not commingle his own funds with the trust funds. So he does not have access to gains on the trust, notwithstanding part of his money is there.
Trustee is only entitled to take back the money he put in the trust (that is $10,000).
The gains ($20,000) and initial money of the trust ($10,000) all goes to the trust (total amount of $30,000).