Google S/W Engineer interview questions

They asked recursion problem where I need to compute the number of ways I can climb the stairs. I can climb either one or two steps at a time. The question is to express the number of the ways I can climb the stairs in terms of the number of step, N Say, T(N)=T(N-1)+T(N-2).... Later I was asked other questions but I didn't understand the question itself. The question itself was not well defined.