Joey studies 2 hours a night 5 nights a week so that's 2*5 = <<2*5=10>>10 hours
He studies 3 hours a day on the weekends so that's 3*2 = <<3*2=6>>6 hours
In one week, Joey studies 10+6 = <<10+6=16>>16 hours
He has 6 weeks till his exams and he studies for 16 hours a week so that's 6*16 = <<6*16=96>>96 hours of studying
#### 96