Solve the Problem $=c$ , Where $P$ Is the Pressure $\mathrm{V}$ Is the Volume, And

Multiple Choice

Solve the problem.
-Boyle's law states that if the temperature of a gas remains constant, then PV $=c$ , where $P$ is the pressure, $\mathrm{V}$ is the volume, and $\mathrm{c}$ is a constant. Given a quantity of gas at constant temperature, if $\mathrm{V}$ is decreasing at a rate of $9 \mathrm{in} .3 / \mathrm{s}$ , at what rate is $\mathrm{P}$ increasing when $\mathrm{P}=70 \mathrm{lb} / \mathrm{in}^{2}$ and $\mathrm{V}=80$ in. 3 ?

A) $\frac{63}{8} \mathrm{lb} / \mathrm{in}^{2}{ }^{2} \mathrm{~s}$
B) $\frac{72}{7} \mathrm{lb} / \mathrm{in}^{2}{ }^{-\mathrm{s}}$
C) $\frac{49}{64} \mathrm{lb} / \mathrm{in}^{2}{ }^{-\mathrm{s}}$
D) $\frac{5600}{9} \mathrm{lb} /$ in. $^{2}-\mathrm{s}$