Greatest Common Divisor (GCD) of 144 and 165
The greatest common divisor (GCD) of 144 and 165 is 3.
What is the Greatest Common Divisor (GCD)?
The GCD of two integers is the largest positive integer that divides both numbers without leaving a remainder. It is useful in simplifying fractions, finding common factors, and in number theory.
How to Calculate the GCD of 144 and 165?
We use the Euclidean algorithm, which involves the following steps:
- Divide the larger number by the smaller number.
- Replace the larger number with the smaller number and the smaller number with the remainder from the division.
- Repeat this process until the remainder is zero.
- The non-zero remainder just before zero is the GCD.
Step-by-Step Euclidean Algorithm
| Step | Calculation |
|---|---|
| 1 | 144 ÷ 165 = 0 remainder 144 |
| 2 | 165 ÷ 144 = 1 remainder 21 |
| 3 | 144 ÷ 21 = 6 remainder 18 |
| 4 | 21 ÷ 18 = 1 remainder 3 |
| 5 | 18 ÷ 3 = 6 remainder 0 |
Examples of GCD Calculations
| Numbers | GCD |
|---|---|
| 159 and 142 | 1 |
| 180 and 174 | 6 |
| 138 and 77 | 1 |
| 174 and 99 | 3 |
| 78 and 31 | 1 |