Eighty percent of the time, pressing the green (left) button will be the correct choice. However, 20% of the time, it will be wrong choice. Thus, if you press the green button all of the time, you will be right most of the time, but you will be wrong some of the time. Your goal is to get as many correct responses as you can in 10 button presses.
To get them all right, you will probably have to press the red button 2 times during the 10 trials. So, if you want to get 100% right, you will have to take advantage of both your knowledge of the green button being right most of the time and your intuition. It may, however, be that trying to be perfect will make you do worse than someone--or even a rat--who just presses the green button.
Good luck!
Rats get about 80% right. Are you doing better or worse than a rat?
If you "see" a pattern, you are wrong. There is no pattern: You are being fooled by randomness.