From

OG 12th edition:

If the two floors in a certain building are 9 feet apart, how many steps are there in a set of stairs that extends from the first floor to the second floor of the building?

(1) Each step is 3/4 of a foot high

(2) Each step is 1 foot wide

OA:

I thought it was

because the stairway can be extended in many different ways, e.g. at different slopes, or it can even go up in one direction, and then in the other (sort of zig-zag). Also, each consecutive stair doesn't have to extend by its full height.

I guess if you assume that the stairs are placed in one direction, and the next begins where the previous ends (height wise) then A is the answer, but to me it seems that this assumption was not explicated in the question.

The distance given between two floors is in height, not slope or width. so if we consider 1st and 2nd floor it is the height which is 9 ft between both of them. SO how much ever slope we will give to the stairs their height should sum to 9 ft dats y we can conclude from the first point dat no of stairs = 9 ft / 3/4 ft

or 12 sets. This is why A is the answer.