A level Chemistry cracking

Hi,
I’ve been doing some questions on this and they only give you the cracking equation and then ask what type of cracking it was, I’m confused about how to tell if it was thermal or catalytic - is it just that thermal forms a higher proportion of alkene molecules than catalytic? Or is there another rule I can use?

Thanks!
The ones I was talking about only gave you their molecular formula so I couldn’t tell whether or not it was branched. I’m guessing it wasn’t a very good question and they’d have to give you some kind of hint?