Identify the word which belongs to the class of given words. Grams, Kilograms,…

In a word-classification reasoning question, three (or more) of the given words share one common category — here, a type of measurement unit — and the task is to find which option shares that same category. The method is: first identify the common attribute of the given words, then test every option against that attribute; the option matching it is the answer, and every other option belongs to a different category.

Grams, Kilograms, and Quintal are all metric units used to measure mass (weight), so the required shared category here is "unit of mass". Checking the options against this category: Tonnes is also a metric unit that measures mass, so it belongs to the same group as the given words.

• Yard measures length or distance, not mass.

• Litre measures volume or liquid capacity, not mass.

• Kilometer measures long distance, not mass.

Since Tonnes is the only option that shares the mass/weight category with Grams, Kilograms, and Quintal, it is the word that belongs to the given class.