What force is required to hold a marble slab weighing 1 ton in water?

The plate in the water is affected by the force of Archimedes and the force of gravity. These forces are exactly the opposite. To hold the plate in water, it is necessary to apply a force in the direction of the Archimedes force.
Р = mg – ρgV, where m is the mass of the slab (m = 1 t = 1000 kg), g is the acceleration of gravity (g = 9.8 m / s ^ 2), ρ is the density of water (ρ = 1000 kg / m ^ 3), V is the slab volume (V = m / ρ, where ρ is the density of the marble, ρ = 2700 kg / m ^ 3).
P = 1000 * 9.8 – 1000 * 9.8 * 1000/2700 = 9800 – 3630 = 6170 N.
Answer. A force of 6170 N is required to hold the marble slab.