Guessing games is one of the easiest way to get prizes or rewards. The rewards from this minigame is never the same, it ranges from Energy, Fame points, Coins, Art points, etc.
There's absolutely no strategy to this minigame, just try your best to choose the right answer since the rewards are better then if you choose a wrong answer (Yes, you still get a reward even if you choose the wrong answer)
Just click on the "Guessing games" option on your left side of the screen.
And just try your best to choose the right answer.