What is the approximate average body weight of an adult blue whale?

Introduction / Context:
The blue whale is famous as the largest animal known to have ever lived on Earth. This question checks whether you know the approximate average body weight of an adult blue whale, expressed in kilograms and tonnes. Such facts are common in school level science and general knowledge exams.

Given Data / Assumptions:

We are considering an adult blue whale of typical size, not the absolute heaviest recorded specimen. Weight is expressed both in kilograms and as an approximate value in tonnes. Options range from a few thousand kilograms to very large values.

Concept / Approach:
Blue whales are massive marine mammals. Standard references usually state that an adult blue whale can weigh around 100 to 150 tonnes, with some individuals possibly reaching close to 200 tonnes. One tonne is equal to 1,000 kilograms. Therefore, a ballpark estimate of 150 tonnes corresponds to 150,000 kilograms. This value lies within the typical range and matches the upper part of the average figures quoted for large adult blue whales, making it a suitable answer for a general knowledge question.

Step-by-Step Solution:
Step 1: Recall that many reliable sources say a blue whale weighs roughly between 100 and 150 tonnes on average. Step 2: Convert these values to kilograms. One hundred tonnes equals 100,000 kilograms and 150 tonnes equals 150,000 kilograms. Step 3: Check the answer options. Only the options around 100,000 and 150,000 kilograms fall within this realistic range. Step 4: The option with 150,000 kilograms, or about 150 tonnes, best represents a typical large adult blue whale and matches widely quoted approximate values. Step 5: Values like 5,000 kilograms or 15,000 kilograms are much too small and would reflect the weight of smaller whales or other large animals, not a blue whale.

Verification / Alternative check:
You can cross check by comparing the blue whale with elephants. An adult African elephant weighs up to about 6 tonnes. If a blue whale weighs around 150 tonnes, that is roughly the same as 25 large elephants, which is a commonly repeated comparison in educational materials. This again supports the idea that we are dealing with many tens or hundreds of thousands of kilograms, not a few thousand. Remembering that blue whales are the absolute giants of the animal world helps you ignore options that are obviously too small.

Why Other Options Are Wrong:
A weight of around 5,000 kilograms or 15,000 kilograms is far too low and is closer to the mass of large land mammals or smaller whale species, not a blue whale. Around 50,000 kilograms, or 50 tonnes, is still much smaller than typical estimates for adult blue whales. Around 100,000 kilograms is within the lower part of the blue whale range, but the question asks for the approximate average, and general knowledge references often highlight a figure nearer 150 tonnes. Therefore, around 150,000 kilograms is the most appropriate choice among the given options.

Common Pitfalls:
Students sometimes underestimate large animal weights because numbers above 100,000 kilograms feel abstract. Others may confuse the blue whale with smaller whale species or with the overall average for many whales, rather than this particular giant species. A good strategy is to anchor your memory with a simple fact such as a blue whale weighing around 100 to 150 tonnes and use that to evaluate any option you see in an exam. This prevents you from choosing unrealistic small values.

Final Answer:
The approximate average body weight of an adult blue whale is around 150,000 kilograms (about 150 tonnes).