Funny, but I don't think the first and third are real.
I'll try to explain limits to my 11 years old son tomorrow. I'll see how he will answer.

Today I tested him with the cutting board question. I promised him to buy a new PC game if he answer correctly. He immediately answered 15 seconds  => 2 parts for 10 seconds => 1 part = 10/2 = 5 seconds. 3 parts = 15 seconds. (wrong). I told him that he's wrong and he answered correctly. No new game for now.

Limits are learning in college I think. We'll see can I explain it well.