What is the Least Common Multiple of 7920 and 7940?

Least common multiple or lowest common denominator (lcd) can be calculated in two way; with the LCM formula calculation of greatest common factor (GCF), or multiplying the prime factors with the highest exponent factor.

Least Common Multiple of 7920 and 7940 with GCF Formula

The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 7920 and 7940, than apply into the LCM equation.

GCF(7920,7940) = 20
LCM(7920,7940) = ( 7920 × 7940) / 20
LCM(7920,7940) = 62884800 / 20
LCM(7920,7940) = 3144240

Least Common Multiple (LCM) of 7920 and 7940 with Primes

Least common multiple can be found by multiplying the highest exponent prime factors of 7920 and 7940. First we will calculate the prime factors of 7920 and 7940.

Prime Factorization of 7920

Prime Factorization of 7940

Now multiplying the highest exponent prime factors to calculate the LCM of 7920 and 7940.

LCM(7920,7940) = 2⁴ × 3² × 5¹ × 11¹ × 397¹
LCM(7920,7940) = 3144240