To find the cost to ship the box, you will find the total mass and then calculate the cost based on your total mass.
1. 2.75 + (5 x 1.65) = 11 kg (total mass)
2. $40 (for the first 5 kg) + $3.15 x 6 (for the remaining 6 kg) = $58.90
The cost to ship the box is $58.90.