The deepest mine in the world, East Rand mine in South Africa, reaches $3585 \;m$ into earth's crust. Another African mine western Deep is being deepened to $4100\;m$. Suppose the temperature at the top of the mine shaft is $11^{\circ}c$ and that increases at a rate of $0.015^{\circ}c$ at you descend. <br><br> QUESTION : What is the temperature at the bottom of each mine.

Question

$\begin{array}{1 1} (a)\; 65^{\circ}c,70^{\circ}c \\ (b)\; 65^{\circ}c,73^{\circ}c \\ (c)\; 70^{\circ}c,65^{\circ}c \\(d)\; 73^{\circ}c,65^{\circ}c \end{array}$