[udaygrover]

Look at it like this

there are 2 options with each question
1. u solve it
2. u dont solve it

so possible ways are 2 for each question

now if u have 2 questions

possible ways =2*2

extend the logic to 6 q's
possible ways = 2^6

hope it clears some doubts

n we reduce the 1 in the answer...
well im sure every1 knows that by now

uday