Verified Answer :

Easy, now many might not know certain formulas of cylinders.

But, for this equation we must use the formula:

h= \frac{V}{ \pi r^{2} }

It's saying to find the Height (h) divide the volume by \pi and the radius squared.

So, plug it in,

(It's trying to trick you by saying 187.5 \pi , but mutiply it to get 589)

h= \frac{589}{ \pi 6.25}

which is

h= \frac{589}{19.6}

h=30

Thus,your answer is 30. (A)

moonlightbelle

The volume of all prisms is v=bh. This case is no different, except it just so happens that the base is a circle.

*Reminder: area of a circle = pi×r^2 (pi times radius-squared)

Plug 2.5 into the place of r. Now you should have pi2.5^2, which simplifies to pi6.25.

Now, you have the base. But you don't know the height. You are given the total volume though.

187.5pi = pi6.25 × h

Just divide pi6.25 from both sides of the equal sign and you will be able to find the height.


Work:
-> 187.5pi = bh
-> 187.5pi = pi6.25 × h
-> 187.5pi/pi6.25 = pi6.25/pi6.25 x h
-> 30pi = h

So, the answer should be A.