1st letters of each term are : C, E, G, ?, K We can observe that these are alternate alphabets of english alphabets Hence, we can say that the first alphabet of the missing term will be I 2nd letter of each term are: A,E,I,?,U We can observe that there is gap of exactly 3 alphabets between any 2 consecutive terms. Hence we can say that the second alphabet of the missing term will be 0 3rd letter of each term are :T, R, P, ?, L We can observe that these are alternate alphabets in descending order. Hence we can say that the third alphabet of the missing term will be N