Greatest Common Divisor (GCD) of 129 and 85
The greatest common divisor (GCD) of 129 and 85 is 1.
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 129 and 85?
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 | 129 ÷ 85 = 1 remainder 44 |
| 2 | 85 ÷ 44 = 1 remainder 41 |
| 3 | 44 ÷ 41 = 1 remainder 3 |
| 4 | 41 ÷ 3 = 13 remainder 2 |
| 5 | 3 ÷ 2 = 1 remainder 1 |
| 6 | 2 ÷ 1 = 2 remainder 0 |
Examples of GCD Calculations
| Numbers | GCD |
|---|---|
| 13 and 179 | 1 |
| 71 and 32 | 1 |
| 117 and 198 | 9 |
| 25 and 156 | 1 |
| 167 and 20 | 1 |