1. Add the total weight of the shipping box and it's inner items.
2.75+(5*1.65)=11 kilograms
2. Subtract the 5kg from 11kg to get the extra 6kg that was over 5kg.
3. Since it costs $3.15 for each kilogram and you have 6 kilograms, you just multiply the cost ($3.15) by 6 which is $18.9
4. Add together the costs of 5kg ($40) and 6kg ($18.9)
40+18.9=$58.9
The cost to ship the packed box was $58.9.