Anyway, while I'm supposed to be doing homework, I'll give you a serious answer.
The only way you're going to figure this out is if you compare the evidence.
"P" and "J" aren't functions but are a part of the shorthand that abbreviates for the functions.
ENTJ: Te, Ni, Se, Fi
and
ENTP: Ne, Ti, Fe, Si
As you can see, they're really quite different. Also, these create an archetype, something that is not going to fit any person perfectly, but you're looking for best fit, correct? You always are with MBTI, anyway...
But simply talking about P and J. A combination of functions will either orient towards gathering information (P) or making decision (J). Both types can do both, but one is generally more natural to each person, the usual mode of living. While a P type may be called upon to make a decision and then they do it, a J type will decide, decide, decide, decide, decide all the time whether outside forces tell them to or not because that's just how they function and find it easier to live.
All people will seem "P" sometimes, and all people will seem "J" sometimes. Generally, an ENTJ will seek to order things outside of them to suit a vision of what they think will 'work better.' ENTPs are more suited towards information gathering. It really has nothing to do with the appearance of 'chaos' (which, if they are ENTJ, there's likely a method to their madness) or outgoing and friendliness. The only thing I see there that might affect P versus J is 'flexibility,' though. A J type will generally seem less flexible than a P type, but also, there are situations where a J may allow for flexibility, or find the situation requiring flexibility inevitable and force themselves around it without too much fuss -- especially an NT, who can easily find a logical reason why something could not have been avoided, and will likely just suck it up and plough on through anyway.
How well do you really know them? Take a really good look at their habits. Also, if they're interested in MBTI, coerce them into a discussion about it, and find a way to point out your thoughts on their perceived type. They will likely have justification for whatever type they claim to be. If they could care less about MBTI and just took the test because you told them to, don't bring it up and continue silent observation.