Greatest Common Divisor (GCD) of 138 and 155
The greatest common divisor (GCD) of 138 and 155 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 138 and 155?
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 | 138 ÷ 155 = 0 remainder 138 |
| 2 | 155 ÷ 138 = 1 remainder 17 |
| 3 | 138 ÷ 17 = 8 remainder 2 |
| 4 | 17 ÷ 2 = 8 remainder 1 |
| 5 | 2 ÷ 1 = 2 remainder 0 |
Examples of GCD Calculations
| Numbers | GCD |
|---|---|
| 36 and 191 | 1 |
| 59 and 72 | 1 |
| 90 and 33 | 3 |
| 111 and 158 | 1 |
| 178 and 178 | 178 |