Answer: 2
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Explanation:
Focus on the first row only. This involves the stem 2 and various leaves. The stem 2 refers to having a tens digit of 2. So it involves the numbers 20 through 29.
More narrowly, we're involving the values: 20, 22, 24, 24, 27, 29. Each value corresponds to exactly one leaf in that first row. For example, a stem of 2 and a leaf of 7 combine to form the number 27. Often, there will be a key at the bottom of the stem-and-leaf plot to indicate this in shorthand (eg: 2|7 means 27).
In that first row, we see the value 24 shows up twice. This means that there are 2 floors where there are 24 offices on those floors.
