Como Hallar los nuevos calados para un buque mercante?

A ship is floating at drafts of 6.1 metres F and 6.7 metres A. The following
cargo is then loaded:
20 tonnes in a position whose centre of gravity is 30 metres forward of
amidships.
45 tonnes in a position whose centre of gravity is 25 metres forward of
amidships.
60 tonnes in a position whose centre of gravity is 15 metres aft of
amidships.
30 tonnes in a position whose centre of gravity is 3 metres aft of
amidships.
The centre of flotation is amidships, MCT 1cm=200 tonnes m and
TPC = 35 tonnes. Find the new drafts forward and aft.

Hallar en base de estos datos el nuevo calado.