A lemon. It’s a citrus fruit whose juice is acidic and can be used to conduct electricity for motors. A car or other purchase that has problems is known as a lemon and can be expensive to repair. Lemons have a tart flavor but do little harm (unless you get it in a cut, then it hurts like the dickens). The old saying goes, “When life gives you lemons, make lemonade” (I know, it’s spelled aid not ade but it sounds the same and wouldn’t make any sense the other way. It all works out nicely when the riddle is told instead of read.)
You are given eight coins and told that one of them is counterfeit. The counterfeit one is slightly heavier than the other seven. Otherwise, the coins look identical. Using a simple balance scale, how can you determine which coin is counterfeit using the scale only twice?
First weigh three coins against three others. If the weights are equal, weigh the remaining two against each other. The heavier one is the counterfeit. If one of the groups of three is heavier, weigh two of those coins against each other. If one is heavier, it’s the counterfeit. If they’re equal weight, the third coin is the counterfeit.
What looks like food, tastes like food, smells like food, sounds like food when you cook it, is grown in dirt like food, fills up your stomach like food, but is not food?
A poisonous mushroom. Since some types of mushrooms are edible, it can be very hard to distinguish between a safe mushroom and one that will kill you. Food is defined as a substance consumed to provide nutrition, therefore a poisonous mushroom that kills you doesn’t qualify as food, even though it shares all of the traits of a regular mushroom.
Other valid answers include anything that’s edible, resembles food, but is poisonous.
Someone preserving food. The two most common ways of preserving food are canning and freezing. So when you preserve food, if you can can it, you do, otherwise you freeze it.
A snail creeps 10 feet up a wall during the daytime, then falls asleep. It wakes up the next morning and discovers it slipped down 6 feet. If this happens each day, how many days will it take to reach the top of a 20 foot wall?