To find the surface area of the rectangular prism, we need to calculate the area of all six rectangles and then add them together.
First rectangle: 3m x 1.5m = 4.5m²
Second rectangle: 3m x 4m = 12m²
Third rectangle: 3m x 1.5m = 4.5m²
Fourth rectangle: 3m x 4m = 12m²
Fifth rectangle: 4m x 3m = 12m²
Sixth rectangle: 4m x 3m = 12m²
Total surface area = 4.5m² + 12m² + 4.5m² + 12m² + 12m² + 12m²
Total surface area = 57m²
Therefore, the surface area of the rectangular prism is 57m².