All GMAT Math Resources
Example Questions
Example Question #1 : Understanding Measurement
Restate 100 miles per hour in feet per second (rounded to the nearest whole number).
One mile is equal to 5,280 feet, and one hour is equal to 3,600 seconds, The speed can be converted as follows:
or, rounded, 147 feet per second.
Example Question #51 : Word Problems
Convert to Fahrenheit (to the nearest tenth).
The Celsius-to-Fahrenheit conversion formula is:
Substitute 45 for :
The answer is .
Example Question #52 : Word Problems
Convert to degrees Celsius (nearest whole degree).
If is the Fahrenheit temperature, then the equivalent Celsius temperature is
.
Substitute into the equation.
This rounds up to .
Example Question #53 : Problem Solving Questions
Using the conversion factor 2.54 centimeters = 1 inch, rewrite 100 square inches in square centimeters (nearest tenth).
1 inch = 2.54 centimeters, so 1 square inch = square centimeters.
100 square inches are equal to square centimeters, which rounds to 645.2 square centimeters.
Example Question #53 : Word Problems
Jason skips a rock across the surface of a pond. The rock bounces three times over the pond's surface. If the second bounce is half the distance of the first bounce, and the third bounce is one quarter of the second bounce, and the total distance between bounces is 65 inches, how many inches did the rock travel on the first bounce?
We need to translate the words into a mathematical equation. Since we need to solve for the distance the rock travels on the first bounce, let's use a variable to represent that distance.
Let "" = distance traveled on the first bounce.
Notice that we can describe the distances traveled on the 2nd and 3rd bounces in terms of :
Distance traveled on the 2nd bounce is half the distance of the 1st bounce, so 2nd bounce =
Distance traveled on the 3rd bounce is 1/4 of the 2nd bounce, so, 3rd bounce =
The total distance, then, is:
Example Question #54 : Word Problems
Three years ago, Anna was four times as old as Jeff. Today Anna is three times as old as Jeff.
How old was Anna three years ago?
First, we set up the variables and the equations. Let:
= Anna's age three years ago
= Jeff's age three years ago. So:
= Anna's age today
= Jeff's age today
Therefore: and . Then we solve for the system of equations:
or
When we solve for J first we get .
Then we solve for A using the first equation of the system:
Therefore Anna was 24 years old three years ago.
Example Question #14 : Measurement Problems
kilometer is approximately inches. How many kilometers are there in inches?
Since
,
Therefore we multiply 1,170,000 by 1/(3.9*104) to obtain the number of kilometers in 1,170,000 inches.
Example Question #57 : Gmat Quantitative Reasoning
If one liter of gasoline costs , how much would eighteen gallons of gasoline cost? (One gallon is approximately liters.)
One gallon of gasoline is about liters of gasoline. The number of liters in eighteen gallons is:
One liter costs . Therefore, eighteen gallons ( liters) will cost:
Example Question #58 : Gmat Quantitative Reasoning
If an object travels at a speed of 10 feet per second, how many feet does it travel in half an hour?
If an object travels at 10 feet per second, then in half an hour it will travel 10 feet for every second there is in 30 minutes. We can set this multiplication up as follows:
Here we can see that the units of seconds are cancelled after the first operation, and the units of minutes are cancelled after the second operation, leaving us with the unit of feet for our answer.
Example Question #55 : Word Problems
Fill in the blank:
One pound is equal to 16 ounces.
Multiply:
52 ounces is the correct choice.