Greatest Common Divisor (GCD) of 69 and 129
The greatest common divisor (GCD) of 69 and 129 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 69 and 129?
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 | 69 ÷ 129 = 0 remainder 69 |
| 2 | 129 ÷ 69 = 1 remainder 60 |
| 3 | 69 ÷ 60 = 1 remainder 9 |
| 4 | 60 ÷ 9 = 6 remainder 6 |
| 5 | 9 ÷ 6 = 1 remainder 3 |
| 6 | 6 ÷ 3 = 2 remainder 0 |
Examples of GCD Calculations
| Numbers | GCD |
|---|---|
| 197 and 117 | 1 |
| 66 and 194 | 2 |
| 140 and 74 | 2 |
| 159 and 152 | 1 |
| 28 and 147 | 7 |