Loading a weight to produce a required draft

$19$ A ship $120$ m long floats in salt water at drafts $5\mathrm{.}8$ m F and $6\mathrm{.}6$ m A $.$ TPC $15$ tonnes. MCT $1cm=300$ tonnes m $.$ Centre of flotation is amidships.

What is the minimum amount of water ballast required to be taken into the forepeak tank $($centre of gravity $60$ m forward of the centre of flotation$)$ to reduce the draft aft to $6\mathrm{.}5$ metres? Find also the final draft forward.