When a cylindrical tank is filled with water at a rate of 22 cubics meters per hour, the level of water in the tank rises at a rate of 0.7 meters per hour. Which of the following best approximates the radius of the tank in meters?
$$A.\ \frac{\sqrt{10}}{2}$$
$$B.\ \sqrt{10}$$
$$C.\ 4$$
$$D.\ 5$$
$$E.\ 10$$
The OA is B.
We are basically told that a cylinder with a height of 0.7 (7/10) meters has the volume of 22 cubic meters, right?
We know that
$$V_{cylinder}=\pi r^2h=22\ \Rightarrow \pi\approx\frac{22}{7}\ \Rightarrow \frac{22}{7}\cdot r^2\cdot\frac{7}{10}=22\ \Rightarrow r=\sqrt{10}$$
Is there a strategic approach to this PS question? Can any experts help me, please? Thanks!
$$A.\ \frac{\sqrt{10}}{2}$$
$$B.\ \sqrt{10}$$
$$C.\ 4$$
$$D.\ 5$$
$$E.\ 10$$
The OA is B.
We are basically told that a cylinder with a height of 0.7 (7/10) meters has the volume of 22 cubic meters, right?
We know that
$$V_{cylinder}=\pi r^2h=22\ \Rightarrow \pi\approx\frac{22}{7}\ \Rightarrow \frac{22}{7}\cdot r^2\cdot\frac{7}{10}=22\ \Rightarrow r=\sqrt{10}$$
Is there a strategic approach to this PS question? Can any experts help me, please? Thanks!
