take 2 min to find easy questions and 1st solve them.
then take 2 min find more questions and solve them.
and if u can't do good in Maths then spend more time in Chemistry or Physics basic questions.
try to score more then to solve Maths questions.
and go for practise for the topics u find SIMPLE.
It is not the time to improve ur weakness now, rather to prove ur STRENGTH.
It is good to solve 1 question 10 times before JEE then to solve 10 questions only once.
so go for it!!!