Completion of Letter Series

Introduction: In this question, we are given a letter series with gaps in between. We need to find a set of letters that can be placed sequentially in the gaps to complete the series.

Approach: We need to observe the pattern in the given letter series and find a set of letters that follows the same pattern.

Given Letter Series:

itca __ bd __ ec __ fd __ gef

Observations:

- The first letter is 'i'.
- The second letter is 't' which is two letters ahead of 'i' in the English alphabet.
- The third letter is 'c' which is two letters behind 't' in the English alphabet.
- The fourth letter is 'a' which is two letters ahead of 'c' in the English alphabet.
- The fifth letter is 'b' which is two letters behind 'a' in the English alphabet.
- The sixth letter is 'd' which is two letters ahead of 'b' in the English alphabet.
- The seventh letter is 'e' which is two letters behind 'd' in the English alphabet.
- The eighth letter is 'c' which is two letters ahead of 'e' in the English alphabet.
- The ninth letter is 'f' which is two letters behind 'c' in the English alphabet.
- The tenth letter is 'd' which is two letters ahead of 'f' in the English alphabet.
- The eleventh letter is 'g' which is two letters behind 'd' in the English alphabet.
- The twelfth letter is 'e' which is two letters ahead of 'g' in the English alphabet.
- The thirteenth letter is 'f' which is two letters behind 'e' in the English alphabet.

Solution:

From the above observations, we can see that the pattern followed in the given letter series is as follows:

- The first letter is 'i'.
- From the second letter onwards, we have a sequence of letters that are two letters apart from each other in the English alphabet.
- The sequence of letters alternates between going two letters ahead and two letters behind in the English alphabet.

Using this pattern, we can find a set of letters that can be placed sequentially in the gaps to complete the series. The set of letters is:

a) b c d e

If we place these letters sequentially in the gaps, we get the completed letter series as:

itcabedecfddgef

Therefore, option A is the correct answer.