What is the mass of a body if, when it is lifted by 4 m, its potential energy has increased by 100 J?

As you know, the potential energy of a body raised above the Earth is equal to:
Ep = m * g * h, where m is the mass of the body, g is the acceleration of gravity of a body raised above the Earth’s surface = 9.8 N / kg, h is the height of the body.
Let for the initial stage the potential energy:
Ep = m * g * h
After climbing 4 meters, the potential energy is:
Ep2 = m * g * h2
From the conditions:
Ep2-Ep = 100J
h2-h = 4m
mass and acceleration are constants.
Ep2-Ep = m * g * h2-m * g * h = m * g * (h2-h), we express the mass from this expression:
m = (Ep2-Ep) / (g * (h2-h)) = 100 / 9.8 * 4 = 2.55 kg
Answer: body weight 2.55 kg.