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Least Common Multiple (LCM) of 42 and 21

The least common multiple (LCM) of 42 and 21 is 42.

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 42 and 21?

First, calculate the GCD of 42 and 21 using the Euclidean algorithm. Then use the formula above to find the LCM.

Step-by-Step GCD Calculation

StepCalculation
1 42 ÷ 21 = 2 remainder 0

Examples of LCM Calculations

NumbersLCM
167 and 325344
36 and 1521368
79 and 18114299
53 and 1196307
128 and 946016

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