(a) A guardian of an infant ward, in the investment both of the funds of the estate and of other property of the infant which he may receive, shall be governed by the laws which govern investments by a guardian of an infant who has executed and filed a bond with surety.
(b) A guardian of an incompetent ward, in the investment both of the funds of the estate and other property of the incompetent which he may receive, shall be governed by the laws which govern investments by a committee of an incompetent.