Least Common Multiple (LCM) of 21 and 47
The least common multiple (LCM) of 21 and 47 is 987.
What is the Least Common Multiple (LCM)?
The LCM of two integers is the smallest positive integer that is divisible by both numbers. It is often used to find common denominators and solve problems involving periodic events.
Formula for LCM
The LCM of two numbers can be calculated using their GCD:
LCM(a, b) = |a × b| ÷ GCD(a, b)
How to Calculate the LCM of 21 and 47?
First, calculate the GCD of 21 and 47 using the Euclidean algorithm. Then use the formula above to find the LCM.
Step-by-Step GCD Calculation
| Step | Calculation |
|---|---|
| 1 | 21 ÷ 47 = 0 remainder 21 |
| 2 | 47 ÷ 21 = 2 remainder 5 |
| 3 | 21 ÷ 5 = 4 remainder 1 |
| 4 | 5 ÷ 1 = 5 remainder 0 |
Examples of LCM Calculations
| Numbers | LCM |
|---|---|
| 125 and 36 | 4500 |
| 17 and 101 | 1717 |
| 38 and 77 | 2926 |
| 150 and 51 | 2550 |
| 156 and 72 | 936 |