Greatest Common Divisor (GCD) of 121 and 78
The greatest common divisor (GCD) of 121 and 78 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 121 and 78?
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 | 121 ÷ 78 = 1 remainder 43 |
| 2 | 78 ÷ 43 = 1 remainder 35 |
| 3 | 43 ÷ 35 = 1 remainder 8 |
| 4 | 35 ÷ 8 = 4 remainder 3 |
| 5 | 8 ÷ 3 = 2 remainder 2 |
| 6 | 3 ÷ 2 = 1 remainder 1 |
| 7 | 2 ÷ 1 = 2 remainder 0 |
Examples of GCD Calculations
| Numbers | GCD |
|---|---|
| 146 and 134 | 2 |
| 46 and 50 | 2 |
| 181 and 103 | 1 |
| 53 and 67 | 1 |
| 43 and 175 | 1 |