Answer:
Total number of ways will be [tex]=8.44727\times 10^{10}ways[/tex]
Step-by-step explanation:
We have to select 7 countries
3 countries selected from a block of 54
So number of ways of selecting these three countries [tex]=^{54}c_3=\frac{54!}{3!51!}=\frac{54\times 53\times \times 52\times 51!}{6\times 51!}=24804ways[/tex]
Now 1 country is selected from 66 block
So number of ways to select 1 country = [tex]=^{66}c_1=\frac{66!}{1!65!}=\frac{66\times \times 65!}{1\times 65!}=65ways[/tex]
Now next 3 country is selected from 69 country
So [tex]=^{69}c_3=\frac{69!}{3!66!}=\frac{69\times68\times 67 \times 66!}{6\times 66!}=52394ways[/tex]
So total number of ways to select 7 countries = 24804×65×52394 [tex]=8.44727\times 10^{10}ways[/tex]
