"Plausible idiot" is a good way to describe it. It's so easy to trick. Here's an example:
Q My friend has two tokens and I have six, but I owe one to my friend. There is a toy that costs 7 tokens. Can my friend and I afford to buy it?
A No, your friend and you cannot afford to buy the toy that costs 7 tokens. Even though your friend has two tokens and you have six tokens, you owe one token to your friend, so you only have five tokens available to spend. When you combine your friend's two tokens with your five tokens, you only have a total of 7 tokens, which is not enough to buy the toy that costs 7 tokens. In this case, your friend and you do not have enough money to buy the toy, even though you have a total of seven tokens when you combine your individual amounts. It is important to remember that when combining the amount of money two or more people have, you should add their individual amounts together, but also take into account any debts or obligations that need to be paid. In this case, your friend and you do not have enough money to buy the toy because you owe one token to your friend.
... "you only have a total of 7 tokens, which is not enough to buy the toy that costs 7 tokens"... ;-))) It doesn't seem to listen to what it's saying. Also, the patronizing paragraph it adds to most of its answers is quite ridiculous, given how clueless it is.