Objects on the moon's surface have an acceleration due to gravity one-sixth that on the earth's. What would the 5 0 kg boy weigh on the moon?

Gravititional acceleration on earth is approximately 9.8m/s²

The weight of the boy is directly proportional to his gravitational acceleration.

This is correct according newton's equation of bodies in motion:

Force (Also equal to weight) = Mass * Acceleration due to gravity

Here the mass is constant.

Hence decreasing the gravitational acceleration of the boy by 1/6 consequently reduces his weight by 1/6.

Therefore the boy weighs ⇒ 1/6 * 5kg * 9.8m/s² = 8.2N (rounded off to 1 decimal value)