How much would a 65kg person weigh on mars?

All you need to know to answer this question is the acceleration due to gravity on Mars, which is 3.71 m/s. Plugging that number into the equation F = m*gm, where F is the force on the object due to gravity, also called its weight, m is the mass of the object and gm is the acceleration due to gravity on Mars. The result is

185.5 kg*m/s or 185.5 N.