See attachment for the full solution.
Analyze the data one digest at a time. Draw circular or line drawings for each to help you visualize the data.
The first digest involves only one enzyme, HaeII. The resulting fragment size from the plasmid cut with HaeII is one band of 12kb. From this piece of data, you can assume two likely clues: 1. HaeII cuts only one time because plasmids are rarely 24kb long, and 2. the total size of your plasmid is 12kb. All of your other digests should have pieces that add up to 12. Any time an enzyme only cuts one time, the size of the resulting fragment is the total size of your plasmid. (Note: just because there is one band doesn't necessarily mean it only cuts one time. We see this in the fifth digest.)
The second digest involves a single enzyme, but results in two bands that add up to 12kb. This corroborates the idea that HaeII is truly a single cutter. Now you can be more confident that PstI is an ...
This solution explains how to draw a possible restriction map for a circular plasmid.