How to find the greatest common factor - GRE Math (2024)

FAQs

How to find the greatest common factor - GRE Math? ›

The greatest common factor is the greatest factor that divides both numbers. To find the greatest common factor, first list the prime factors of each number. 18 and 24 share one 2 and one 3 in common. We multiply them to get the GCF, so 2 * 3 = 6 is the GCF of 18 and 24.

The Greatest Common Factor (GCF) of two or more integers is the greatest integer that is a factor of each of the original numbers. For example, the GCF of 12 and 9 is 3, because the prime factors of 12 are 3 and 2, and the factor of 9 is 3, and so 3 is the largest common factor.

The highest common factor is found by multiplying all the factors which appear in both lists: So the HCF of 60 and 72 is 2 × 2 × 3 which is 12. The lowest common multiple is found by multiplying all the factors which appear in either list: So the LCM of 60 and 72 is 2 × 2 × 2 × 3 × 3 × 5 which is 360.

What is a good GRE score? For most programs, it's 75th percentile or above: 157+ in Verbal Reasoning and 165+ in Quantitative Reasoning. For top programs, it's a 90th percentile score or higher: 162+ in Verbal and 169+ in Quant.

The GRE Score Percentiles

So, a 70th percentile GRE Quantitative score (currently 163) means that you scored better in Quant than 70% of recent GRE test-takers. Likewise, a 70th percentile GRE Verbal score (currently 156) means that you scored better in Verbal than 70% of recent GRE test-takers.

To find common factors of two numbers, first, list out all the factors of two numbers separately and then compare them. Now write the factors which are common to both the numbers. These factors are called common factors of given two numbers.

To find the greatest common factor of two or more natural numbers, there are 3 methods that can be used - listing out of the common factors, prime factorization, and division method. Each method requires division and multiplication to obtain the GCF. For example, the GCF of 14 and 35 is 7.

To simplify a ratio, divide all parts of the ratio by their highest common factor. For example, the highest common factor of both parts of the ratio 4:2 is 2 , so 4:2=2:1 4 : 2 = 2 : 1 .

What is the greatest common factor of 72 and 90? ›

∴ The greatest common factor of 72 and 90 is 2 × 3 × 3 = 18.

The greatest common factor is the greatest factor that divides both numbers. To find the greatest common factor, first list the prime factors of each number. 18 and 24 share one 2 and one 3 in common. We multiply them to get the GCF, so 2 * 3 = 6 is the GCF of 18 and 24.

As an easy example, let's say you need to find the GCF for 16 and 20. All you do is subtract 16 from 20, to get the difference, 4, and this number — 4 — is the largest number that could POSSIBLY go into both 16 and 20 evenly. Once you know that, just test 2, 3, and 4 to find the highest one that goes into 16 and 20.

How do you find the GCF? Step 1: State the product of prime factors for each number. Step 2: Write all the prime factors for each number into a Venn diagram. Step 3: Multiply the prime factors in the intersection to find the GCF.

With the GREs, scoring in the 90% percentile doesn't mean you got an A- on the test, it means you scored better than 90% of all other test-takers. In a nutshell: Your GRE percentile is not your raw score or a grade; it is a reflection of how well you did compared to others.

A score of 165 is in the 95th percentile, meaning that if you score 165 in the Verbal or Quantitative Section, you will be in the top 5% of all test takers. If so, the GRE score will be a strong positive factor for your application.

For Verbal, 152 is the 50th percentile. That means, only a score of 153 or higher will put you above this benchmark for the Verbal section. Quant scores skew slightly higher. 156 is 49th percentile, while 157 is 52nd percentile.