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From a solid cube of side 24 cm, a cuboidal cavity of square cross-section of side 9 cm is hollowed along one surface from one edge to the opposite edge. What is the volume (in cm 3 ) of the remaining solid?
11880
13095
8640
12055 Question ID : 44100925521 Option 1 ID : 441009101789 Option 2 ID : 441009101787 Option 3 ID : 441009101790 Option 4 ID : 441009101788 Status : Answered Chosen Option : B
11880
Calculate volume of cube (243=13824) and subtract volume of the rectangular bar removed (9├Ч9├Ч24=1944). Since 13824тИТ1944=11880, the result is straightforward.
Side of solid cube = 24 cm, side of square cross-section of cuboidal cavity = 9 cm, length of cavity = 24 cm (from one edge to opposite edge).
VremainingтАЛ=VcubeтАЛтИТVcavityтАЛ=(s3)тИТ(a2├Чl)
Calculate volume of cube (243=13824) and subtract volume of the rectangular bar removed (9├Ч9├Ч24=1944). Since 13824тИТ1944=11880, the result is straightforward.
Students often misinterpret 'from one edge to the opposite edge' as a diagonal cut or fail to recognize that the cavity length equals the cube's side length.
Calculate Volume of the solid cube
The volume of a cube is given by V=s3, where s is the side length.
VcubeтАЛ=243=13824┬аcm3
Calculate Volume of the cuboidal cavity
The cavity is a cuboid with square cross-section 9┬аcm├Ч9┬аcm and length equal to the cube side 24┬аcm.
VcavityтАЛ=9├Ч9├Ч24=81├Ч24=1944┬аcm3
Calculate Remaining Volume
Subtract the cavity volume from the total cube volume to find the remaining material.
VremainingтАЛ=13824тИТ1944=11880┬аcm3
A is correct because the volume of the original cube is 13824 and subtracting the 1944 volume of the hollowed cuboid results in 11880.
This concept of 'subtraction of volumes' is frequently used in engineering aptitude tests involving material removal processes like milling or drilling.