A box of nails weighs 130 pounds when it is 2/3 full. It weighs 74 pounds when it is 3/8 full. What is the weight of the box?

Let the weight of the full Volume of nails in the box be W. Let the weight of the box be B. 2/3 W  + B =  130 ........i          From the first statement. 3/8 W  + B =      74 ......ii         From the second statement. Equation (i)  Minus (ii) 2/3 W  - 3/8 W + B  - B =  130 - 74 (16W  - 9W) / 24                 = 56 7W / 24  =  56. W        =  56 * 24 / 7 W        =    192  Pounds. Substituting V = 64 in equation (i) 2/3 W  + B =  130 2/3 * 192  + B =  130 2 * 64  + B =  130 128  + B =  130 B =  130 -128 = 2. Therefore, weight of box, B = 2 pounds.