SQL Server: query to retrieve aggregated data using variables

Question:
Summarize events using the MIN, MAX and COUNT functions

Help:
To do this, create variables to maintain each of the aggregates:

Variable What will eventually contain
@EarliestDate The earliest date
@LatestDate The last date
@NumberOfEvents The number of events
@EventInfo The Event Summary title

Now use a single SELECT clause to set the value of all these variables (alternatively, you could use a series of subqueries).

Write another SELECT clause to show the value of the variables, to show the summary output shown above.

Result:

enter the description of the image here

I'm having trouble doing this exercise.

Is there any place where I can get the solution?

Thanks in advance!