Analyze and judge.

What are the two related quantities in the question?

Since 1.5 square decimeter floor tiles and 2 square decimeter floor tiles are laid in the same room, that is, the area is equal, it can be determined that the number of floor tiles is inversely proportional to the area of each floor tile.

Second step

Set unknown x.

Solution: use 2 square decimeters of floor tile X. Step 3

Column equation.

According to the meaning of inverse proportion, the equation can be listed:

2x= 1.5*200

Fourth step

Solve the equation and find X.

x= 150

Step five

Test and write the answers.

Substitute x= 150 into the equation, and the left and right sides are equal, that is, the number of floor tiles is inversely proportional to the area of floor tiles, which is consistent with the meaning of the question. So the solution is correct.