Answer :
Weight of body in planet is 1798.17 N
Explanation:
Weight = Mass x Acceleration due to gravity
In Earth
784 = Mass x 9.81
Mass = 79.92 kg
Mass of body = 79.92 kg
Mass is a constant, it will not change planet to planet.
In planet
Weight = Mass x Acceleration due to gravity
Weight = 79.92 x 22.5
Weight = 1798.17 N
Weight of body in planet is 1798.17 N