A word series is given as: cry, dome, super, random, ?. Choose the correct alternative from the given options that will logically complete the series when you observe the pattern in the length of each word.

Introduction / Context:
This is a verbal series question where the terms of the series are words rather than numbers. The words cry, dome, super, and random may not look connected by meaning, so the key is to search for a structural pattern. One simple but powerful observation for such series is the number of letters in each word.

Given Data / Assumptions:

• Given series: cry, dome, super, random, ?
• Options: reflex, done, formula, classify, planet.
• We assume that the pattern is based on objective observable properties such as spellings or lengths, not on subjective meanings.
• Exactly one option should follow the pattern consistently.

Concept / Approach:
When dealing with a word series, you can check several possible patterns: alphabetical order of first letters, vowels and consonants, meaning based groups, or word length. If the meanings are unrelated and the letters do not follow a simple alphabetical pattern, the length of each word is often the intended basis of the series. Here, checking the number of letters quickly reveals a clear progression.

Step-by-Step Solution:
Step 1: Count the number of letters in each given word. Step 2: cry has 3 letters, dome has 4 letters, super has 5 letters, and random has 6 letters. Step 3: We can see that the series is increasing by one letter each time: 3, 4, 5, 6. Step 4: To continue this pattern, the next word in the series should have 7 letters. Step 5: Now examine the options and count their letters: reflex (6 letters), done (4 letters), formula (7 letters), classify (8 letters), planet (6 letters). Step 6: Only formula has 7 letters, which matches the required next term in the pattern of word lengths. Step 7: Therefore, formula is the correct choice to complete the series cry, dome, super, random, formula.

Verification / Alternative check:
As a quick check, write the lengths directly: cry (3), dome (4), super (5), random (6), formula (7). This gives a simple sequence 3, 4, 5, 6, 7, which is a natural and consistent progression. None of the other options fits this pattern, since they either repeat an earlier length or jump too far.

Why Other Options Are Wrong:
reflex has 6 letters, which would repeat the length of random rather than extend the pattern. done has only 4 letters, which would break the increasing sequence and move backwards in length. classify has 8 letters, which skips directly from 6 to 8 and does not continue the step size of one. planet has 6 letters and therefore duplicates the length of random instead of increasing it.

Common Pitfalls:
Students sometimes search for complex patterns in letter positions or meanings and overlook the simplest structural clue, which here is word length. Another frequent error is to be attracted by words that look semantically related, even when the series is not based on meaning. Always check numeric properties such as counts and positions before overcomplicating the problem.

Final Answer:
The word that correctly completes the increasing word length pattern is formula.