If appears in the your game chat (Default) an question in orange color, don't waste time.
(You have only 5 minutes to answer the question.)

Find in the game a button in the upper left corner called by Answer.

Once open, type the answer and press the ok button.

If you get the answer wrong you have to wait till the next question, but if you get the answer right you will receive the Question Box. Use the box to take your reward.
(This Box may contains a koete coin)