Input-Output Questions for RBI GRADE B

What is Input-Output

A machine receives an initial line of words and numbers called the Input. It then rearranges them step by step following a fixed hidden rule. Each step is called a Step (Step 1, Step 2, etc.), and the process ends at the Final Step when no further rearrangement is possible. Your job is to find the rule by comparing two or three given steps, then answer questions about a specific step or the final output.

• Input is the starting line with mixed words and numbers.
• Each step applies the same rule repeatedly until arrangement is complete.
• The rule can involve sorting words alphabetically, sorting numbers ascending or descending, or alternating word-number placement.
• Questions ask: What is Step 3? What is the final step? Which step gives a specific arrangement?
• Always decode the rule before attempting any question in the set.
• The total number of steps equals the number of elements minus one in most simple patterns.

Common Patterns in RBI Grade B

RBI Grade B prelims favour slightly complex dual-rule patterns where words and numbers are arranged simultaneously. For example, in each step the smallest number moves to the leftmost position AND the alphabetically last word moves to the rightmost position. This dual movement is the most frequently tested variant. Another common pattern is alternating arrangement where one element goes left and another goes right in a single step.

• Pattern 1 Dual Sort: Smallest number to left, largest word (alphabetically last) to right in each step.
• Pattern 2 Reverse Dual Sort: Largest number to left, alphabetically first word to right.
• Pattern 3 Word-Number Alternating: Words settle on odd positions, numbers on even positions step by step.
• Pattern 4 Single Sort: Only numbers are sorted (ascending or descending), words stay in original order.
• Always check at least 2 consecutive steps before concluding the rule.
• Count how many elements shift per step to estimate total number of steps.

Step-by-Step Method to Crack the Rule

Do not jump to questions. Spend 90 seconds decoding the rule first. Compare the Input with Step 1 and note exactly which element moved and where. Then compare Step 1 with Step 2 to confirm the same rule applied again. Once confirmed, apply it forward to find any required step or backward to reconstruct a missing step.

• Step A: Read Input and Step 1 side by side. Identify what changed.
• Step B: Confirm the same change in Step 1 to Step 2.
• Step C: Label the rule clearly in your rough sheet before solving.
• Step D: For forward questions, apply the rule repeatedly from the last given step.
• Step E: For backward questions, reverse the rule to reconstruct earlier steps.
• Step F: Count the final step number to verify your answer makes sense.

Tricky Variants to Watch

Some sets use a point-based or value-based rule where the numerical value of the word (sum of position of letters) determines arrangement order. Others use word length instead of alphabetical order. RBI Grade B has introduced such variants in recent years to increase difficulty. The solution approach remains the same — decode by observation — but these take 30 extra seconds to spot.

• Word length variant: shorter word goes left or right instead of alphabetical rule.
• Sum of digits variant: elements are arranged by digit sum, not face value.
• Mirror step variant: the arrangement in each step mirrors the previous step partially.
• Shift-by-one variant: each element shifts one position left or right in a fixed pattern.
• When confused between two possible rules, test on Step 2 to Step 3 to eliminate the wrong one.

• Jumping to questions without fully decoding the rule — causes wrong answers on all 4-5 questions in the set.
• Assuming only one element moves per step when actually two elements move simultaneously (dual rule pattern).
• Forgetting that already arranged elements at the left or right do not move in subsequent steps — they are locked in position.
• Miscounting the step number when reconstructing forward — always re-verify by applying the rule from the given step, not from memory.
• Confusing alphabetically last with alphabetically first — write A B C on your rough sheet and mark directions clearly.

• DECODE BEFORE YOU DO: Rule first, questions second. Never reverse this order.
• SL-WR mnemonic for the most common pattern: Smallest number goes Left, last Word (alphabetically) goes Right.
• Locked Ends analogy: Think of each step as placing one brick on the left wall and one brick on the right wall. Once placed, bricks never move again.
• 2-Step Confirmation Rule: Always verify the rule on TWO consecutive steps, not just one, before trusting it.

• RBI Grade B Prelims typically gives one Input-Output set with 4 to 5 questions — solving it correctly is a high-ROI activity since you spend effort once but score 4-5 marks.
• The difficulty is medium to medium-high; expect a dual-rule pattern (numbers AND words moving simultaneously) rather than a simple single-sort rule.
• Time budget: spend 90 seconds decoding the rule and about 30-40 seconds per question after that. Total set should take under 4 minutes.
• If you cannot decode the rule in 90 seconds, skip the set and return later — do not let one tricky set drain your time in a 60-minute paper.
• Recent trend: examiners use 8-element inputs (4 words + 4 numbers) which produce exactly 4 steps, making Step 4 the final step — use this to cross-check your answer.