Question 1

Find the odd one out from the following group:
Pencil, Pen, Eraser, Sharpener

Accepted Answer

The question tests classification based on primary function and usage in writing. Pencil, Pen, and Eraser are all used directly in the process of writing or correcting written work on paper. Pencil makes marks, Pen makes marks, and Eraser removes marks — all three are active writing tools. Sharpener, however, is a maintenance tool used to prepare the pencil before writing; it is not used during the actual writing process itself. Therefore, the answer is D (Sharpener).

Question 2

Find the odd one out:
A) Carrot
B) Potato
C) Tomato
D) Onion

Accepted Answer

The classification principle is based on the part of the plant that is consumed as food. Carrot (root vegetable), Potato (tuber/underground stem), and Onion (bulb) are all underground plant parts harvested for consumption. Tomato, however, is a fruit (botanically a berry) that grows above ground on the plant. Therefore, Tomato is the odd one out. Answer is C.

Question 3

In a group of words, find the one that does NOT belong with the others based on a consistent classification principle.

Pencil, Eraser, Sharpener, Notebook

Accepted Answer

The classification principle is: items used to WRITE or MARK on paper versus items used to REMOVE or PREPARE writing instruments.

Pencil: used to write/mark on paper
Eraser: used to remove pencil marks from paper
Sharpener: used to prepare a pencil for writing (maintains the writing instrument)
Notebook: a surface on which one writes

Three items (Pencil, Eraser, Sharpener) are directly involved in the writing process as tools or consumables. Notebook is the MEDIUM or SURFACE on which writing occurs, not a tool in the writing process itself. It serves a different functional role—it is what you write ON, not what you write WITH or what maintains writing instruments.

Therefore, the answer is D (Notebook).

RRB Group D Classification / Odd One Out

Classification / Odd One Out— Rules & Concept

Key Points to Remember

Exam-Specific Tips

Classification / Odd One Out — Practice Questions

60-Second Revision — Classification / Odd One Out