Greatest Common Divisor (GCD) of 30 and 87
The greatest common divisor (GCD) of 30 and 87 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 30 and 87?
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 | 30 ÷ 87 = 0 remainder 30 |
| 2 | 87 ÷ 30 = 2 remainder 27 |
| 3 | 30 ÷ 27 = 1 remainder 3 |
| 4 | 27 ÷ 3 = 9 remainder 0 |
Examples of GCD Calculations
| Numbers | GCD |
|---|---|
| 111 and 124 | 1 |
| 35 and 106 | 1 |
| 103 and 148 | 1 |
| 151 and 68 | 1 |
| 188 and 31 | 1 |