"Published in Newark, California, USA"
An electric refrigerator is built in the form of a rectangular parallelepiped. The inside dimensions are 3 ft. by 2.6 ft. by 1.8 ft. A freezing unit (1.1 ft. by 0.8 ft. by 0.7 ft.) subtracts from the storage room of the box. Find the capacity of the refrigerator.
Solution:
To illustrate the problem, it is better to draw the figure as follows
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| Photo by Math Principles in Everyday Life |
There are two rectangular parallelepiped in the figure, the storage room and the freezing unit of a refrigerator. The cooling unit of a refrigerator is equal to the difference of two rectangular parallelepiped.
For the storage room of a refrigerator, the volume of a rectangular parallelepiped is
For the freezing unit of a refrigerator, the volume of a rectangular parallelepiped is
Therefore, the volume or the capacity of the cooling unit of the refrigerator is
