will the exam format of december 2014 be the same as june 2015?

I assume you mean June 2015 - and the answer is NO! Look at the "Syllabus" section of the OT course notes or visit the ACCA website to see the new structure which now incorporates multiple choice questions

Thank you sir. I actually meant the section b part. Is it still going to be question one(1) income tax etc. Thank you.

I wanted to ask that since section A now is gonna have mcqs...do we have to show the working ?

Firstly - in Section B all we know is that there will be 4 questions of 10 marks each and 2 questions of 15 marks each. The 2 questions of 15 marks will be on Income tax and Corporation tax and in the specimen paper they were the final 2 questions on the paper. For the MCQ's no workings required just your choice of letter from A to D

What will be the best plan...starting with section a or b....if i want to complete the paper on time ..?

There is no best plan, it is down to the individual and what is right for you. Given that you have 15 minutes reading time it would appear sensible, however to use this time to answer several of the MCQ's but you should not spend time on what you find to be "difficult" questions. These should be left to the end of the exam after you have completed the written section as it is very easy to waste a lot of time on just a few MCQ's that you may well get wrong anyway and therefore score no marks - that time is much better spent on the written questions. If you then run out of time at the end of the paper you should only have outstanding the 2 or 3 most difficult MCQ questions which you can then make a calculated guess at to complete the paper!