Greatest Common Divisor (GCD) of 72 and 172
The greatest common divisor (GCD) of 72 and 172 is 4.
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 72 and 172?
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 | 72 ÷ 172 = 0 remainder 72 |
| 2 | 172 ÷ 72 = 2 remainder 28 |
| 3 | 72 ÷ 28 = 2 remainder 16 |
| 4 | 28 ÷ 16 = 1 remainder 12 |
| 5 | 16 ÷ 12 = 1 remainder 4 |
| 6 | 12 ÷ 4 = 3 remainder 0 |
Examples of GCD Calculations
| Numbers | GCD |
|---|---|
| 135 and 55 | 5 |
| 33 and 168 | 3 |
| 48 and 30 | 6 |
| 157 and 163 | 1 |
| 143 and 46 | 1 |