Sentence Correction

Hi
Can anybody please clarify whether following sentences have noun modifier or adverb modifier:

Happy about his raise, he took his friends out for dinner.

Exhausted from her job, she decided to leave.

As per MGMAT, second sentence has adverbial modifier while they seem to classify first sentence under noun modifier category. I dont really get the difference. True that second sentence has a past participle, but modifier phrases in both sentences seem to be serving the same purpose.

I believe that the reason second one has been classified as adverb modifier, is because the modifier is answering the question: Why did she decide to leave.

However, I feel that second one is acting as a noun modifier as well, because the participle is modifying the noun "she".

May be a Manhattan instructor can add valuable comments.