Students would be more successful if they got cash for passing exams.

Anybody could think that if you offer money to a child they would improve their scores immediately, but according to a report I have just read, it says that parents could be wasting their money because kids don´t show progress. If you want to motivate them to learn, you could offer them something they like, for example a trip to somewhere, go to (tickets / an outing) to the cinema or go to the theater. Finally what it is the most important for children is the way they are taught, so this involves teachers directly to teachers and their ways to motivate them to learn.

Interesting what drives motivation - not always what we think!