All GRE Math Resources
Example Questions
Example Question #1501 : Gre Quantitative Reasoning
What is the surface area of a cylinder with a radius of 6 and a height of 9?
96π
108π
64π
180π
225π
180π
surface area of a cylinder
= 2πr2 + 2πrh
= 2π * 62 + 2π * 6 *9
= 180π
Example Question #2 : Solid Geometry
Quantitative Comparison
Quantity A: The volume of a cylinder with a radius of 3 and a height of 4
Quantity B: 3 times the volume of a cone with a radius of 3 and a height of 4
Quantity A is greater.
The relationship cannot be determined from the information given.
The two quantities are equal.
Quantity B is greater.
The two quantities are equal.
There is no need to do the actual computations here to find the two volumes. The volume of a cone is exactly 1/3 the volume of a cylinder with the same height and radius. That means the two quantities are equal. The formulas show this relationship as well: volume of a cone = πr2h/3 and volume of a cylinder = πr2h.
Example Question #1501 : Gre Quantitative Reasoning
A right circular cylinder of volume has a height of 8.
Quantity A: 10
Quantity B: The circumference of the base
Quantity B is greater
The two quantities are equal
Quantity A is greater
The relationship cannot be determined from the information provided.
Quantity B is greater
The volume of any solid figure is . In this case, the volume of the cylinder is and its height is , which means that the area of its base must be . Working backwards, you can figure out that the radius of a circle of area is . The circumference of a circle with a radius of is , which is greater than .
Example Question #1502 : Gre Quantitative Reasoning
What is the surface area of a cylinder that has a diameter of 6 inches and is 4 inches tall?
The formula for the surface area of a cylinder is ,
where is the radius and is the height.
Example Question #311 : Geometry
A cylinder has a radius of 4 and a height of 8. What is its surface area?
This problem is simple if we remember the surface area formula!
Example Question #4 : How To Find The Surface Area Of A Cylinder
Quantitative Comparison
Quantity A: Surface area of a cylinder that is 2 feet high and has a radius of 4 feet
Quantity B: Surface area of a box that is 3 feet wide, 2 feet high, and 4 feet long
Quantity B is greater.
The two quantities are equal.
Quantity A is greater.
The relationship cannot be determined from the information given.
Quantity A is greater.
Quantity A: SA of a cylinder = 2πr2 + 2πrh = 2π * 16 + 2π * 4 * 2 = 48π
Quantity B: SA of a rectangular solid = 2ab + 2bc + 2ac = 2 * 3 * 2 + 2 * 2 * 4 + 2 * 3 * 4 = 52
48π is much larger than 52, because π is approximately 3.14.
Example Question #2 : Cylinders
A cylinder has a height of 4 and a circumference of 16π. What is its volume
none of these
256π
64π
128π
16π
256π
circumference = πd
d = 2r
volume of cylinder = πr2h
r = 8, h = 4
volume = 256π
Example Question #1502 : Gre Quantitative Reasoning
Rusty is considering making a cylindrical grain silo to store his crops. He has an area that is 6 feet long, 6 feet wide and 12 feet tall to build a cylinder in. What is the maximum volume of grain that he can store in this cylinder?
The maximum cylindrical base can have a diameter of 6 and therefore a radius of 3. The formula for the volume of a cylinder is , which in this case is .
Example Question #2 : How To Find The Volume Of A Cylinder
A cylinder with volume of and a radius of has its radius doubled. What is the volume of the new cylinder?
To begin, you must solve for the height of the original cylinder. We know:
For our values, we know:
Now, divide both sides by :
So, if we have a new radius of , our volume will be:
Example Question #1503 : Gre Quantitative Reasoning
If the dimensions of a rectangular crate are , which of the following CANNOT be the total surface area of two sides of the crate?
Side 1: surface area of the 6 x 7 side is 42
Side 2: surface area of the 7 x 8 side is 56
Side 3: surface area of the 6 x 8 side is 48.
We can add sides 1 and 3 to get 90, so that's not the answer.
We can add sides 1 and 1 to get 84, so that's not the answer.
We can add sides 2 and 3 to get 104, so that's not the answer.
We can add sides 2 and 2 to get 112, so that's not the answer.
This leaves the answer of 92. Any combination of the three sides of the rectangular prism will not give us 92 as the total surface area.