Hello there...

From your question it's clear that you've not studied anything for last 3 years or due to your job you were totally away from the studies. But now you want to prepare for Banking exams .

So it's really possible for you to prepare for Banking exams well .The only thing you need to be focused and  hardworking (considering that you've lost your rhythm of studying for something).

Banking exams like IBPS,SBI and others ask basic questions ,it's syllabus includes(Quantitative aptitude, English, Reasoning and sometimes also computer knowledge and general awareness) . you can solve quantitative aptitude questions easily if you've a good grasp over the basic things you've studied in your upto class 10th level .

I would like to tell you that first of all be positive about your dedication to prepare for exams ,don't think like you've not studied anything for 3 years.

Know the syllabus and pattern , take relevant materials and do your preparation.if you'll not  feel comfortable then you can also take any coaching institute's class course which will help you to do your preparation well.

At last I would like to tell you that in banking exams key factor is your speed and accuracy so work upon them .

Best of luck

Thanks

I hope it'll be helpful...