A.) 1
Type it in your calc. to find
Answer:

Step-by-step explanation:
the volume of a cylinder is given by:

where r is the radius and h is the height.
and the surface area:

the first term is the area of the circles and the second term is the area of the body.
since "The number of volume of a cylinder is half of its number of the total surface area." we will have that:

substitutig the equivalent expressions on each side:

and we simplify and solve for the height (since is the value we don't know of the cylinder):

we substitute the value of the radius
, and we get:

thus the volume is:


Answer:
c
Step-by-step explanation:
Divide the total the lake holds by the number of days:
400 million / 25 days = 16 million gallons per day.
The standard form of the equation of a circle is:

Where the point (a,b) represents the centre and r is the radius. So, given your information, the equation will be: