ask simple riddles. those should be available to answer to most of the players of different ages/cultural backgrounds. simple ones are:
1) a red house is made out of red bricks.
a blue house is made out of blue bricks.
what is a green house made out of?
- glass
orrrrrrr
2) what can you catch but not throw?
- a cold
see those don't require players to alt+tab out of game to go into google to search for the answer....also these riddles/questions require a bit of thinking so players won't be able to spam answers right away. that's my suggestion although i don't play jail anymore because of the current way the game is played (back out of cell, shift walking, don't move/jump/crouch/look/talk/breathe)...kind of boring and i always get free killed