1. In the following question, which one set of letters when sequentially placed at the gaps in the given letter series shall complete it? a _ c a a b _ a _ b c a a b _ a _ b _ a
2. In the following question, which one set of letters when sequentially placed at the gaps in the given letter series shall complete it? a _ c a a b _ a _ b c a a b _ a _ b _ a
4. In the following question, from the given alternative words, select the word which cannot be formed using the letters of the given word. Nightwalker