tax...theory

Depends for me it may take 3 days

 I think you are here only for time pass,,,,

If you want to gain expertise on DT give a lot of time on it....

Dont ask this type of ques yar.....

JUST FOCUS ON HOW U LEARN...............

U CAN'T LEARN & REMEMBER IT FOR LONG AS U NEED TO REVISE THEM AGAIN & AGAIN

 it completely depends on ur focus,concentration n belief in urself