12th important questions maths chapter-1 chapter-2 chapter-3 chapter-4 chapter-5 chapter-6 chapter-7 chapter-8 chapter-9 chapter-10 chapter-11 chapter-12 physics unit-1 unit-2 unit-3 unit-4 unit-5 unit-6 unit-8 chemistry unit-1 unit-2 unit-3 unit-4 unit-5 unit-6 unit-7 unit-8 unit-9 unit-10 unit-11 unit-12 unit-13 unit-14 unit-15 botany chapter-1 chapter-2 chapter-3 chapter-4 chapter-5 chapter-6 chapter-7 chapter-8 chapter-9 chapter-10 zoology chapter-1 chapter-2 chapter-3 chapter-4 chapter-5 chapter-6 chapter-7 chapter-8 chapter-9 chapter-10 chapter-11 chapter-12 Computer sc. chapter-1 chapter-2 chapter-3 chapter-4 chapter-5 chapter-6 chapter-7 chapter-8 chapter-9 chapter-10 chapter-11 chapter-12 chapter-13 chapter-14 chapter-15 chapter-16