I don't believe they can pass the exam,_______?does he can't he doesn't he can they

I don't believe they can pass the exam,_______?does he can't he doesn't he can they
I don't believe they can pass the exam,_______?
does he can't he doesn't he can they

I don't believe they can pass the exam,_______?does he can't he doesn't he can they
can they?