The diagram in your answer booklet represents an observer standing near the side of a building. using the
scale shown, place an x on the side of the building to show the maximum height of the tsunami that killed
thousands of people as it engulfed towns on the northern coast of japan. [1]

Hi,

Unfortunately there is no scale or no picture of the building attached, but when you read the text there is one - and only one information that can be used and useful in this task:

"shook buildings across Japan and generated a 7-meter-high tsunami"

So the mark will be at 7 meters high. Depending on how your picture of the building is, you have to find the 7 meters mark and place your X there!