1. Trustees’ Duty to Act in the Best Interest of Beneficiaries: The trustees are under a duty to act in the best interest of the beneficiaries as directed by the terms of the trust. In this case, the trustees were instructed to invest the sum of N5 million and apply the income to the education of the beneficiaries. The trustees must follow this directive unless otherwise provided by the terms of the trust or by law.
2. Obligation to Preserve the Trust Fund: Trustees have a fiduciary duty to preserve the trust fund for the purpose for which it was set up. This duty overrides any requests made by the beneficiaries if the request contradicts the purpose of the trust.
3. Refusal of the Directive: In this instance, the trustees must refuse the directive to pay the N5 million directly to the beneficiaries, as it contradicts the intention of the trust, which was to use the income from the fund for educational purposes. The trustees are required to ensure the trust assets are used as originally intended by the deceased.

Explanation:

This part of the question focuses on the duties of trustees in managing trust funds and emphasizes the importance of adhering to the terms of the trust. Trustees are required to act in the best interest of the beneficiaries but must also ensure that the trust’s purpose is upheld.