Updated March 04, 2010
Out of the three sections, Arithmetic section usually accounts for over 50% of the questions asked in GMAT quantitative section. Some of the important arithmetic concepts for GMAT are number properties, averages and simple operations, and probabilities.
Number Properties and Operations
Some of the properties of numbers you need to know for the GMAT include:
- Integers vs. rational numbers
- Prime numbers vs. composites
- Fractions and percentages
- Even and odd numbers
- Perfect squares and radical expressions (roots)
Of course, you will also need to be able to perform simple operations (addition, multiplication, etc.) with these types of numbers in order to simplify expressions or find values.
Find the value of .
Solving this question requires some knowledge of simple operations in radical numbers and exponent laws. Here’s how you solve this question: , which equals . It’s easy to get confused, so watch out.
X is a prime number that is greater than 21 but less than 42. How many possible numbers can X be?
Here you need to know prime number theory. Going one by one from 21 to 42, you need to check whether each number is prime by trying to factor it. The primes in the range are: 23, 29, 31, 37, 41. Therefore your answer is 5.
is what percentage of ?
Here you need to know fractions and percentages. You need to note that you answer will be more than 100 percent, since 1/32 is less than 1/4. In fact, . Thus, 1/4 is 800 percent of 1/32.
There are more types of arithmetic problems. You need to be able to find averages in various ways. You also need to be familiar with the basics of probability and statistics, as well as permutations and combinations.
The average of A, 2A+5, A+6 and 3A is 29. What’s A?
The formula for Averages means that , so and A = 15.
Below you will find a lot of useful practice tests that will help you increase your GMAT Quant section score.
Practice GMAT Arithmetic Problems
Practice makes perfect!
GMAT Simple Average (10 problems) GMAT Average (10 problems) GMAT Probability Questions (4 problems) GMAT Permutations and Combinations (5 problems) GMAT Arithmetic (10 problems) GMAT Number Theory (10 problems), GMAT Number System (10 problems)