romitvsingh wrote:The area of curved surface of a cylinder is 264m^2.Its volume is 924m^3. The height of the cylinder must be
a 4m
b 6m
c 8m
d none of these
The area of the curved surface of a cylinder = 2(pi)rh
So, if this area is 264, we can write 2(pi)rh = 264
Divide both sides by 2 to get
(pi)rh = 132
The volume of a cylinder = (pi)(r^2)h
So, if the volume is 924, we can write
(pi)(r^2)h = 924
From here, we can "divide" the equations to get:
(pi)(r^2)h/
(pi)rh =
924/
132
Simplify to get:
r=7
Now that we know the value of r, we can plug this value into either equation to find the value of h.
How about: (pi)(
7)h = 132
This means that h = 132/7pi
As you can see, h cannot be an integer, so the answer must be
D.
Cheers,
Brent
