how to solve 100 questions in 60 minutes? eg.IBPS po exam

No one has ever did that!!
someone has to be a super man to do it..
but from my experience i have seen person cracking upto 93 given the paper is very easy .
Here mostly in PO one will attempt a exam in accordance to its toughness and the cut offs vary each year  with respect to the toughness of that exam :)

prepare smartly for any exam ..don't go behind numbers .one will say for eg. he/she has attended 90+ but what matters is your accuracy .
at the end of the day one who gave 90+ with 60 or 70% may get failed and one who attended 70 odd with 100% accuracy passes the exam so it depends on how accurate you are !!!