Blonde Swimming Joke

There were a brunette, a black haired girl, a ranger and a blonde on a island. they were 200km away from safety. they all decided they will swim to safety.
The ranger swam 5km and drowned, the black haired swam 20km and drowned, the brunette swam 50km and drowned. but when the blonde had her turn she swam 100km and said…
“i m tired!”
so she swam all the way back to the island..