You still have time to improve your percentage as you have been a good student with excellent memory.
Accounts is really interesting- I was even obsessed with it! Tallying is a knack- You can work on the formulas in Maths- what else matters?
Another thing: Instead of answering according to the serial order, it would be better if you answered the ones you know the best first, to leave a good impression.
Time yourself. Its not enough if you know it all- you should answer it all & for this time is the key factor.
Best of Luck dear!
I'm sure you'll come out in flying colours!
:D