Question

Find all the numbers less than $100$ which are multiples of $4$ and $5$.

Answer 1

Multiple of $4=4,8,12,16,20,24,28,32,36,40,44,48,52,56,60,64,68,72,76,80,84,88,92,96,100$

Multiple of $5=5,10,15,20,25,30,35,40,45,50,55,60,65,70,75,80,85,90,95,100$

Here, $20$ is the least common multiple of $4$ and $5$.

Therefore, the numbers less than $100$ which are multiples of $4$ and $5$ are $20,40,60,80$.