No. of Links before adding new router

Calculation Final Answer

7(7-1)/2 21

No. of Links after adding new router

Calculation Final Answer

8(8-1)/2 28

Q2.

Total cost of wire before adding new router

Calculation Final Answer

21*5*100 10500

Total cost of wire after adding new router

Calculation Final Answer

28*5*100 14000

Can anyone tell if my answers are correct or wrong?

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2nd Question is wrong correct is like this

Total cost of wire before adding new router

Calculation Final Answer

21*5*100 10500

Total cost of wire after adding new router

Calculation Final Answer

28*5*100 14000