In each of the following questions, two sentences I and II are given. Each sentence has a blank in it. Five words (1), (2), (3), (4) and (5) are suggested. Out of these, only one fits at both the places in the context of each sentence. Number of that word is the answer.

I. He was good with Mathematics so he could not fathorn why other people cribbed about such an ........... subject.

II. In a world so riddled with greed and corruption where every man seems to be out to get another, it is not very ......... to trust others.