One of my cousin don't want to study,how to encourage him to work hard again?

It is not easy to force a guy to do things that he is not interested in. The first step for him to do is that he is supposed to think about his own future. What does he want to do to make a living? How much does he want to make with his poor education? For sure, it is not easy for him to make large amount of money without proper or good education. Besides, he is still too young to go to work in a factory or company. What's more, he doesn't have proper qualification to be engaged in a job. Ask him what he wants to do if he doesn't have the least desire to go to school and let him do some physical labour to see if he enjoys it and how much he will be able to earn. If he is happy with the pay that he will get, let him do what he likes. If not, he will recognize it himself. There is no need to force him to study. Anyway he is at least now sixteen years old. He is supposed to be judgemental about himself in choosing what to do or not. But from the long-term viewpoint, it is still good for him to go on with his study. But if he doesn't want to go to college later, he can go to some technical school to learn some practical skill to enable him to find a good job that he likes. Anyway, try your best to make him realize the importance of learning. Tell him that what he has learnt is his and nobody can steal it from him. Knowledge is power. An ignorant person won't be happy though.

I think you should try to know what he likes first.then choose a proper school for him according to his interests.I think it's not a good idea to pay more money for him to go to a better high school.Once he enter a better one,he'll lose his cofidence if he can't persue his classmates.