here is a scale of a fountain at a museum. the scale is 1:30. how many boulders are in the real fountain

9

Explanation:

When we do a change in scale for a model of something, like a building, all the parts of the building suffer from this change of scale.

Then, the intrinsic properties (like the number of rooms and that) does not change. This means that the number of boulders that we see in the scale will be the same that the number of boulders in the real fountain:

So, if in the scale of the fountain we can see 9 rocks, in the real fountain there also are 9 rocks, just the rocks in the real fountain are larger.

answer; ///blank(1); green bananas; blank(2); raw potatoes;