Mathematics
Assertion (A): The ratio between the edges of three cubes is 2 : 3 : 4. The ratio between their volumes is 4 : 9 : 16.
Reason (R): The ratio between their volumes = 23 : 33 : 43 = 8 : 27 : 64.
- A is true, R is false.
- A is false, R is true.
- Both A and R are true.
- Both A and R are false.
Mensuration
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Answer
A is false, R is true.
Explanation
The given ratio between the edges of the three cubes = 2 : 3 : 4.
Let the edges of the cubes be 2a, 3a and 4a.
Volume of cube = side3
The ratio of the volumes = (2a)3 : (3a)3 : (4a)3
= 8a3 : 27a3 : 64a3
= 8 : 27 : 64
However, the assertion states that the ratio of the volumes is 4:9:16, which is incorrect.
∴ Assertion (A) is false.
As per the reason, the ratio of the volumes is calculated as:
23 : 33 : 43 = 8 : 27 : 64
∴ Reason (R) is true.
Hence, Assertion (A) is false, Reason (R) is true.
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