Top 10 most called numbers by number of calls and Top 10 most called numbers by duration of call

[acg]

I have phone_numbers that were called over time, how often they were called and the duration of each call. 

I need two calculations:

1) Top 10 most called numbers by number of calls received

2) Top 10 most called numbers by duration of call

the varibles I have: Phone_Number , date, call_duration

What DAX can I write to resolve these two calculations?

For Question 1) Top 10 most called numbers by number of calls received: I tried:

                           Top 10 can be resolved with the filter. 

                     
CNT Calls =
CALCULATE (
DISTINCTCOUNT( table[Phone_Number]),
FILTER ( table, table[date])
)

What do I need to change as my count is not correct. The date? How can I write this?

For Question 2) Top 10 most often called numbers by duration of call: I tried:

                           Top 10 can be resolved with the filter. 

CNT of Calls by Duration=
COUNT(
DISTINCTCOUNT( table[Phone_Number]),
FILTER ( table, table[duration])
)

What do I need to change to get the calls by duration?

How can I implement a second filter, say I want only County= AUS ?

Thank you, I am still new to DAX and still find it challenging to get used to. 

[amitchandak · Accepted solution]

@acg , TRy measures like these

calls = count( table[Phone_Number])
Total Duration = Sum(table[duration])

TOP 10 by call = calculate([calls],TOPN(4,allselected(table[Phone_Number]),[calls],DESC), values(table[Phone_Number]))

Top 10 by duration = calculate([Total Duration],TOPN(4,allselected(table[Phone_Number]),[Total Duration ],DESC), values(table[Phone_Number]))

[acg]

@amitchandak I am having trouble to incorporate the Measure: CNT To_Person

and receive the mistake as below. Is the measure at the right place?

CNT To_Person = Count ('mobile mobile_network_calls'[To_Person])

TOP10_by_Call =

CALCULATE([CNT To_Person],TOPN(10,ALLSELECTED('mobile mobile_network_calls'[To_Person],

[CNT To_Person],DESC),VALUES('mobile mobile_network_calls'[To_Person])))

And I receive for   [CNT To_Person],DESC

the follwing mistake:

The ALLSELECTED function expects a table reference expression for argument '2', but a string or numeric expression was used.