Mathematics
If the length of each side of a cube is reduced by 25%, then the ratio of the volumes of the original and the new cube is :
64 : 1
4 : 3
64 : 27
32 : 9
Mensuration
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Answer
Let the original side of cube be a units and side of cube after reduction be a'.
According to the question,
a' = a - 25% of a = a - 0.25a = 0.75a = .
We know that,
Volume of cube = (side)3.
Calculating original volume,
V1 = a3.
Calculating the volume after reduction,
V2 = (a')3
= 3
= a3
Ratio of original volume to the new volume
V1 : V2
a3 : a3
64 : 27.
Hence, option 3 is the correct option.
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