(a) Unless otherwise provided by will, the powers given to two (2) personal representatives may be exercised only by their joint action, and powers given to more than two (2) personal representatives may be exercised only by the joint action of a majority of them.
(b) Every power exercisable by joint personal representatives may be exercised by the survivor of them when one is dead or by the other when one (1) appointment is terminated by order of the court unless the power is given in the will and its terms otherwise clearly provide as to the exercise of the power.