time

Although you should certainly have time to prepare for the June exam, I cannot possibly tell you how many hours you will need. That depends on how easy or how difficult you find each topic. You can see on our website how long each of our lectures takes. You should allow about two weeks after finishing watching all of our lectures (and attempting our shorts tests on each lecture) to spend attempting all of the questions in your Revision Kit.

Which topic is most difficult pls tell

That is impossible for me to answer - every student is different and find different topics easier or harder. You will find out for yourself which you find the most difficult if you work through all of the lectures in chapter order.

I have done topic investment appraisal and working capital and found them pretty easy , so can you please tell will I able to do cost of capital chapter easily?

Again, it is impossible for me to know which topics you will find easy or difficult. You will find out for yourself when you have got to those chapters :-)