What is the LCM of 18 and 28?
LCM of 18 and 28 is the least number which is exactly divisible by both 18 and 28.
Answer: LCM of 18 and 28 is 252
Two methods to find LCM of 18 and 28 are explained below.
The least common multiple of two or more numbers is the smallest number among all common multiples of the given numbers.
- LCM of 18 and 28 by Formula
- LCM of 18 and 28 by Common Division Method
Method 1: LCM of 18 and 28 by Formula
The formula of LCM is LCM (a,b) = (a × b) / GCF (a,b)
The Greatest Common Factor (GCF) of (18, 28) = 2
By using the formula, we get
LCM of 18 and 28 = (18 × 28) / 2
= 504/2 = 252
LCM (18, 28) = 252
Method 2: LCM of 18 and 28 by Common Division Method
Follow the steps mentioned below to find the LCM of 18 and 28 by the common division method.
- Step 1: Write the numbers 18 and 28 horizontally by separating them with a comma.
- Step 2: Choose the smallest prime number that divides at least any one of them.
- Step 3: Write the quotient in the next row just below the numbers. If any of the numbers are not divided, we will bring it down directly.
- Step 4: We will stop it when we don't have a prime number to divide the given numbers.
- Step 5: Least common multiple of 18 and 28 will be the product of primes by which we have divided.
Observe that the solution to our question LCM of 18 and 28 is the same.