Beginner Exercise 105 / Solution

Solution  

is the decisive counter blow. White tries to keep Black separated, since otherwise the purpose of the original moves is defeated...

 

... but now White is caught in a ladder.

White backs down  

White should give up the cutting stones - though the game is already winning for Black.

Weaker  

ko capture is a double atari, but White can keep the cutting stones by sacrificing the other two.