Is is true that whales weigh about 100-150 tons?

That's not quite accurate. While some whales are incredibly large, 100-150 tons is a significant overestimate for most species.

Here's a breakdown:

* The largest whale species, the blue whale, can reach up to 200 tons (around 400,000 pounds).

* Other large whales, like fin whales and humpback whales, weigh around 40-80 tons.

* Smaller whales, like dolphins and porpoises, can weigh anywhere from 100 pounds to a few tons.

So, while some whales do exceed 100 tons, most species are considerably lighter.