Question

A woman has a mass of 50 kg on Earth. What is her mass on the moon?

Answer 1

50 kg. This may be a trick question. Mass is a constant, the amount of resistance a body offers to acceleration. That will not change on the Moon. Weight is the force of gravity on a mass, and of course that WOULD change on the Moon -- it would be much less. So the woman WEIGHS less on the Moon.

Unfortunately, in common usage we tend to equate weight and mass, because we measure mass on Earth by weighing things, since weight is proportional to mass.