I don't understand the difference between 努める{つとめる} and 努力する{どりょくする}。 I encountered the two following sentences:
ごみを少なくするように努める{つとめる}。I will try to reduce waste.
テストで百点が取れるよう努力する{どりょくする}。I will try to get a hundred points in a test.
I translated these words with "try", but I do understand that both verbs have the meaning "putting all your efforts into something", "doing your best to achieve something". I am confused to distinguish any differences between them.
努める is a wago and 努力する is a kango (see the tag wago-and-kango), but in this specific case, 努める happens to be a fairly stiff and/or formal word that is even stiffer than 努力する. Elementary school students seldom use 努める. In informal speech, 頑張る and 努力する are much more common.
The semantic difference between 努める and 努力する is small, but 努める can mean just "to try", whereas 努力する more explicitly means you use lots of time and energy. A time-consuming task like studying goes well with 努力する. On the other hand, reducing household garbage is basically a matter of consciousness and does not usually require a lot of effort, so 努める may be more natural in such cases. 努めて挨拶を行います is natural (although very formal), but 努力して挨拶を行います may even sound like you have some mental or physical problem.
