It looks like the image contains a math problem related to calculating the volume of concrete needed for a set of stairs. The stairs have the same width and height for each step, with the steps increasing in height progressively.

To calculate the volume of concrete, we need to understand the dimensions and how they relate to the shape of the stairs. Based on the provided information:

• Each stair is likely modeled as a rectangular prism.
• The dimensions of each stair are provided as 1.2 meters wide (possibly the width of each stair), and each step is 1.8 meters high.

To find the volume of concrete for the set of stairs, we'll calculate the volume of each step and then sum these volumes.

If you'd like me to continue solving this step by step, let me know, and I can provide more detailed explanations or adjustments as needed!