Answer:
Box 1.
Step-by-step explanation:
The box 1 have the more mass because there are more number of balls present in the box while on the other hand, box 2 has less number of balls in the box. The volume of box boxes are the same as well as weight of the both boxes before placing of balls in it. Placing of balls changes the weight of both boxes because of the presence of different number of balls in each boxes that increases its weight.