Last Updated on May 5, 2023
GMAT OFFICIAL GUIDE DS
Solution:
Let’s sketch a diagram of the stairs. Keep in mind that we don’t know the number of stairs between the floors, but the problem will be easier to solve by first drawing a picture.
From the picture, we can see that if we knew the height of each stair, we could determine the number of stairs that exist between floor one and floor two. Creating an equation we have:
9 feet/(height per step) = number of steps between floors
Statement One Alone:
Each step is 3/4 foot high.
Using the information in statement one we can determine that there are 9/(3/4) = 12 steps between floor 1 and floor 2. Statement one is sufficient to answer the question. We can eliminate answer choices B, C, and E.
Statement Two Alone:
Each step is 1 foot wide.
Knowing only the width of each step does not provide enough information to answer the question.
Answer: A
