A stairway has 100 steps. You can climb it by one step at a time, or by two steps. How many different ways to ascend this stairway exist?

Well the problem seems to be a simple Combination one.
Let us see

From stair 1; one can ascend in
nc0+nc1+nc2+........ncn= 2exp(n)
The next stage is Generalising the whole operation for the rest of the stairs
so we have a gp as
2exp(99)+2exp(98)+2exp(97)........+1
now thats a relief

Ans :2exp(98)

PS:I am always convinced that my solutions are wrong, could someone do that for me please

Posted by Harish on 2003-01-31 23:46:01