What is the weight of the box?

Question

A box weighs 130 pounds when it is 2/3 full. It weighs 74 pounds when it is 3/8 full.

Answer 1

x=weight of the box

y=weight of the contents

x+(2/3)y=130

x+(3/8)y=74

subtract the equations

x+(16/24)y=130

x+(9/24)y=74

(7/24)y=56

multiply both sides by (24/7)

(24/7)(7/24)y=(24/7)56

y=192 pounds, the weight of the contents

x+(2/3)(192)=130

x+128=130

x=2 pounds, the weight of the box

x+(3/8)(192)=74

x+72=74

x=2 pounds again, the weight of the box