Combinatories

Answer : A

Explanation :
The president can be Plected in twenty-six
different ways; following this, the treasurer can
he elected in twenty-five different ways (since the person chosen president is :-:ot eligible to be treasurer); and following this, the secretary can be elected in twenty-four different ways.
Thus, by above principle of counting, there are n = 26 x 25 x 24 = 15 600 different ways in which the organization can elect the officers.