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Differential equations — Question 73

Original QCE Vault practice · 1 mark

Q73 · Practice questionSimple familiar1 mark

QUESTION 73

The volume of a sphere is increasing at 36π cm3 s−136\pi\ \mathrm{cm^3\,s^{-1}}. When the radius is 3 cm3\ \mathrm{cm}, dr/dtdr/dt is
(A)
1 cm s−11\ \mathrm{cm\,s^{-1}}
(B)
3 cm s−13\ \mathrm{cm\,s^{-1}}
(C)
4 cm s−14\ \mathrm{cm\,s^{-1}}
(D)
9 cm s−19\ \mathrm{cm\,s^{-1}}
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