The weight of a body completely immersed in liquid is 2 times less than the weight of this body in air.

The weight of a body completely immersed in liquid is 2 times less than the weight of this body in air. Compare the density of the body and the density of the fluid.

The weight of a body in a liquid is equal to the difference between two directly opposite forces: the force of gravity and the force of Archimedes.
Ft = m * g, where m is the mass of the body (m = ρt * V, ρt is the density of the body, V is the volume of the body), g is the acceleration of gravity.
Fa = ρl * g * V, where ρl is the density of the liquid.
Body weight in air:
Р1 = Fт = ρт * V * g.
Body weight in liquid:
P2 = Ft – Fa = ρt * V * g – ρzh * g * V.
Since Р1 / Р2 = 2, then
ρt * V * g / (ρt * V * g – ρl * g * V) = 2;
ρt / (ρt – ρzh) = 2;
ρt = 2ρt – 2ρzh;
ρt = 2ρzh.
Answer: The density of the body is 2 times the density of the liquid.