A solid of mass 1.3kg,suspended by a string is completely in water. If the tension in the string is 6N,calculate

a)the upthrust on the solid
b)the volume of the solid
c)it's density(density of water is 1000kgm

Please help me find the solution

weight = 1.3 kg * g = 1.3*9.81 = 12.8 Newtons

force up from string = 6 Newtons
so weight of water displaced = 12.8 - 6 = 6.8 Newtons (says Archimedes)
That 6.8 is the upthrust (buoyancy)
volume = mass of water displaced / density = (6.8 / 9.81) /1000 kg/m^3 = 0.693*10^-3 meters^3
density = mass/volume = 1.3 kg / (.693*10^-3) = 1896 kg/m^3
about 1.9 times water density