Answer:
Total number of ways will be

Explanation:
We have to select 7 countries
3 countries selected from a block of 54
So number of ways of selecting these three countries

Now 1 country is selected from 66 block
So number of ways to select 1 country =

Now next 3 country is selected from 69 country
So

So total number of ways to select 7 countries = 24804×65×52394
