All GMAT Math Resources
Example Questions
Example Question #145 : Arithmetic
On a map, one and a half inches represents sixty actual miles. In terms of , what distance in actual miles is represented by inches on the map?
Let be the number of actual miles. Then the proportion statement to be set up, with each ratio being number of actual miles to number of map inches, is:
Simplify the left expression and solve for
Example Question #146 : Arithmetic
The Kingdom of Zenda uses an unusual currency system. It takes 16 kronkheits to make a grotnik and 12 grotniks to make a gazoo.
At current, $1 can be exchanged for 8 grotniks and 8 kronkheits. For how much American currency can a visitor from Zenda exchange a 100-gazoo bill, to the nearest cent?
None of the other choices is the correct amount.
$1 can be exchanged for 8 grotniks and 8 kronkheits, or, equivalently, 8.5 grotniks (8 kronkheits is one-half of a grotnik). 100 gazoos is equal to grotniks. Therefore, if is the number of dollars that can be exchanged for the 100-gazoo bill, we can set up the proportion:
Solve for :
That is, the 100-gazoo bill can be exchanged for $141.18.
Example Question #1 : Ratio & Proportions
In a certain classroom all of the students are either sophomores or juniors. The number of boys and girls in the classroom are equal. Of the girls, are sophomores, and there are 24 junior boys. If the number of junior boys in the classroom are in the same proportion to the total amount of boys as the number of sophomore girls are to the total number of girls, how many students are in the classroom?
This question seems convoluted but is actually more simple than it seems. We are told that the number of girls and boys in the classroom are equal and that of the girls are sophomores. We are then told that 24 of the boys are juniors, and that they represent a proportion of total boys equal to the proportion of sophomore girls to total girls. This means that:
==> where is the total number of boys.
If we know that the number of boys and girls in the class are equal, then the total number of students in the class = 112.
Example Question #1 : Calculating Ratio And Proportion
The Duchy of Grand Fenwick uses an unusual currency system. It takes 24 tiny fenwicks to make a big fenwick.
At current exchange rates, 1 big fenwick can be exchanged for $3.26 American currency. For how much in Grand Fenwick currency can an American tourist exchange $300 (rounded to the nearest tiny fenwick)?
92 big fenwicks and 1 tiny fenwick
108 big fenwicks and 16 tiny fenwicks
None of the other choices gives the correct amount of currency.
296 big fenwicks and 16 tiny fenwicks
40 big fenwicks and 18 tiny fenwicks
92 big fenwicks and 1 tiny fenwick
$3.26 can be exchanged for 1 big fenwick, or, equivalently, 24 tiny fenwicks. We can set up a proportion statement, where is the number of tiny fenwicks for which $300 can be exchanged:
Solve for :
The answer is 2,209 tiny fenwicks, which can be counted up with division:
or 92 big fenwicks and 1 tiny fenwick.
Example Question #2 : Calculating Ratio And Proportion
Five different pizza places offer five different specials. Assuming that all of these pizzas are of the same thickness and that all are of the same quality, which of the following is the best buy?
A 9 inch by 9 inch square pizza for $6.99
A 12 inch by 8 inch rectangular pizza for $9.99
A round pizza 12 inches in diameter for $8.99
A round pizza 10 inches in diameter for $5.99
A 10 inch by 10 inch square pizza for $7.99
A round pizza 10 inches in diameter for $5.99
Since all of the pizzas are of the same thickness and quality, to determine the best bargain, calculate the price per square inch of each. The least amount will mark the best bargain.
Edit this later
A round pizza 10 inches in diameter for $5.99:
The area of the pizza in square inches is
The cost per square inch: or 7.6 cents
A round pizza 12 inches in diameter for $8.99
The area of the pizza in square inches is
The cost per square inch: or 7.9 cents
A 9 inch by 9 inch square pizza for $6.99
The area of the pizza in square inches is
The cost per square inch: or 8.6 cents
A 10 inch by 10 inch square pizza for $7.99
The area of the pizza in square inches is
The cost per square inch: or 8.0 cents
A 12 inch by 8 inch rectangular pizza for $9.99:
The area of the pizza in square inches is
The cost per square inch: or 10.4 cents
The round pizza 10 inches in diameter for $5.99 is the best buy.
Example Question #1701 : Problem Solving Questions
A fathom is a unit of underwater depth equal to six feet.
Express two miles in fathoms.
Multiply 2 miles by 5,280 feet per mile, then divide by 6 feet per fathom:
Example Question #1702 : Problem Solving Questions
A furlong is a measure of length used in horse racing. Eight furlongs are equal to one mile.
Express 20 furlongs in feet.
Divide 20 furlongs by 8 furlongs per mile, then multiply by 5,280 feet per mile.
Example Question #13 : Calculating Ratio And Proportion
127 people signed up for a subscription service. 45 signed up for weekly deliveries, 34 for monthly deliveries, and the rest for annual deliveries. What is the ratio of weekly subscribers to annual subscribers?
Let's first find the number of annual subscribers:
The ratio of weekly subscribers to annual subscribers is therefore .
Example Question #14 : Ratio & Proportions
A clothing store is having a sales for the holiday season. They mark down all items by . What is the sales price of a suit whose original price is ?
We start by finding the value of the mark down:
Therefore, the mark down is 43.8% or 0.438, which means that the new price of the suit is:
Example Question #11 : Ratio & Proportions
Noah and Lilly both work for Company ABC. Lilly earns more than Noah, and each year every employee gets a salary increase. In 2012, Noah's salary was .
What was Lilly's salary in 2013?
We start by finding Lilly's salary in 2012:
$60,000 x 1.20 = $60,000 + $12,000 = $72,000
Then we account for the annual 10% increase to find Lilly's salary in 2013:
$72,000 x 1.10 = $72,000 + $7,200 = $79,200
So Lilly's salary in 2013 was $79,200.