Mathematics · 2020
JEE Main · 9 January 2020, Shift 1 · Q59
A spherical iron ball of 10 cm radius is coated with a layer of ice of uniform thickness that melts at a rate of 50 cm^3 / min. When the thickness of…
A spherical iron ball of $\displaystyle 10$ cm radius is coated with a layer of ice of uniform thickness that melts at a rate of $\displaystyle 50 \mathrm{~cm}^3 / \mathrm{min}$. When the thickness of ice is $\displaystyle 5$ cm, then the rate (in cm/min.) at which of the thickness of ice decreases, is :
Official answer
(3)
$\displaystyle \frac{1}{18 \pi}$
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JEE Main 2020 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.