How do you find the LCM of 8 and 20?

Answer 1

The LCM is: 40. To find the Least Common Multiple (LCM) of any two numbers:

• Find the factors which are common to both numbers; take these once.
• Find the factors which are not common, and take these.
• Multiply the common factors once by the other factors, and that is the Least Common Multiple.

• The factors of 8 are 2 x 2 x 2.
• The factors of 20 are 2 x 2 x 5.

The common factors (2 x 2) are bolded, so this is multiplied by the other non-common factors: (2 x 2) x 2 x 5 = 40.
40