Well this is the first I've heard of someone having trouble at NE 40.
Get all your strengthens up and upgrade as much equipment as you can for that power boost. Also, donate a lot and spend it all on group skills. Group skills increase your power by a lot.
This team shouldn't be too hard with Hinata, Sasuke, Sakura. Or Hinata, Kakashi, Kankuro.
With some strategy, this exam should be doable at around 4000 power. How high is yours? If you're still having trouble, just type in '40' in the search bar and there should be plenty of people that asked this question before you.