Identifying the Missing Letters

The given letter series is: $wwxxyyzz wwx _ yyzz ww _ xyyzz _ wxxyy _ z$.

There are four blank spaces indicated by underscores ($_$).

The task is to find the group of four letters that, when placed sequentially into the blanks from left to right, completes the series.

Evaluating the Options

The options are potential sequences for the blanks:

• 1. $yyxz$
• 2. $xxwz$
• 3. $zxyw$
• 4. $wxyx$

The correct answer is Option B ($xxwz$).

Sequential Filling of Blanks

Using the sequence $xxwz$ for the blanks:

• The first blank (after $wwx$) is filled with $x$.
• The second blank (after $ww$) is filled with $x$.
• The third blank (after $w$) is filled with $w$.
• The fourth blank (after $wxxyy$) is filled with $z$.

Let's substitute these letters into the original series template:

Original: $wwxxyyzz wwx _ yyzz ww _ xyyzz _ wxxyy _ z$

Filled: $wwxxyyzz wwx x yyzz ww x xyyzz w wxxyy z z$

Resulting Pattern Analysis

The completed series, when analyzed segment by segment, shows the following structure:

• Segment 1: $wwxxyyzz$
• Segment 2: $wwxx yyzz$
• Segment 3: $wwx xyyzz$
• Segment 4: $ww xyyzz z$ (formed from $w _ xyyzz _$)
• Segment 5: $wxxyy zz$ (formed from $wxxyy _ z$)

This sequential substitution using the letters $x$, $x$, $w$, $z$ successfully completes the series based on the implied pattern.