Well first use the equation w=mg so if he is 70N you plug that in for w. The gravity on eartg is 9.8. So 70=m(9.8) m= 7.14
Now on the moon the gravity is 1.6m/s sooooo use the mAss u previously found and plug it in. 7.14(1.6)=w w= 11.42 so the weight changes on the moon and earth but the mAss remains the same.
