I have a word problem that is vexing me; the language is getting in the way of my reasoning...

"Let's say we have a circle with a circumference of 10. A tack will be placed somewhere along the circumference of this circle. What is the likelihood it will be placed at the top half of the circumference? What is the likelihood it will placed at exactly the top of the circumference?"

Presumably, the answer to the first question is .5

But what does 'exactly at the top' mean? Couldn't there be an infinite number of places around the circumference for the tack (as no units of measurement are provided)? And how does one determine the top?

Is this a trick logic question or am I missing something?