What is the lcm of 4 and 5?

The LCM (Least Common Multiple) of 4 and 5 is 20.

This means that 20 is the smallest positive integer that is divisible by both 4 and 5 without leaving a remainder.

To find the LCM, you can list the multiples of each number and find the first one they have in common.

Multiples of 4: 4, 8, 12, 16, 20, 24...

Multiples of 5: 5, 10, 15, 20, 25, 30...

The first multiple they have in common is 20, so that is the LCM.