Question 14153
Write the Prime Number factors of each number

100 = 25x4 = 5^2 x 2^2

14 = 2^1 x 7^1

20 = 5x4 = 5^1 x 2^2

Pick the highest number power value of each prime number from all the numbers

So we get 5^2 x 7^1 x 2^2 = 700

And that's your L.C.M or Least Common Multiple