Hi all,
Here is the answer. Congratulations again to those of you who manage to get the answer right. I particularly like Thinzar's explanation.
What is the answer in the blank?

Ans:
RI
Explanation: Look at the first row of letters - R
A, S
C and T
E. The 2nd letter of each pair of letters are A, C and E. The pattern is such that it skips by a letter. A to C skips letter B.
C to E skips letter D.
If you look at the 2nd row of letters - Q
C, R
E and S
G, the 2nd letter of each pair of letters are C, E and G. Again, it skips a letter to get to the next letter. C to E skips letter D.
E to G skips letter F.
This pattern applies to the last row of letters, P
E, Q
G and
?. From E to G, it skips letter F. So, G to ? will skip letter H. As such,the 2nd letter should
I.
If you look at the diagonal row of letters,
RA,
RE and ?, the first letter R is underlined. This is again a pattern and hence, the first letter of ? should be
R.
That makes the answer
RI.