You have now seen H-R diagrams for many different star systems. H-R diagrams can tell you about the ages of star clusters. For instance, a cluster with a lot of blue giants is very young, because those stars burn out very quickly. A typical middle age cluster has most of its stars on the main sequence. An older cluster has a lot of red giants. As the cluster ages even further, you see an increasing number of white dwarf stars.
Create an H-R Diagram for your star cluster. Deduce as much as you can about the age and distance of the cluster by studying its stars.