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If the surface area of a cube is increasing at a rate of 4.8cm²/sec. retaining its shape, then the rate of change of its volume (in cm³/sec.) when the length of a side of the cube is 15 cm is:

Option 1 -

18

Option 2 -

20

Option 3 -

10

Option 4 -

9

0 2 Views | Posted a month ago
Asked by Shiksha User

  • 1 Answer

  • R

    Answered by

    Raj Pandey | Contributor-Level 9

    a month ago
    Correct Option - 1


    Detailed Solution:

    TSA  of cube = 6 a 2

    d d t 6 a 2 = 4.8 ; 12 a d a d t = 4.8 ; a d a d t = 0.4 ; d v d t = d d t a 3 ⇒ 3 a a d a d t

    3 × 15 × 0.4 = 3 × 15 × 04 10 ⇒ 18

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