Before you are 3 glasses, 2 of which stand upside down.
It is given the task - for 3 turns to put all 3 glasses on their base.
Condition: for 1-in turn it is necessary to turn over 2 glasses at the same time. All glasses should be in the correct position only after the third move.
Do you want to see how this should be done?
The answer is: step one.
Answer: step two.
Answer: step three.
That's all! Now all glasses are right!