Find Least Common Multiple of 28, 50, 70 and 140 by listing out the factors.

LCM( 28, 50, 70, 140 ) = 700

Write down multiples of each number until you find the first common multiple:

The multipliers of 28 are: 28, 56, 84, 112, 140, 168, 196, 224, 252, 280, 308, 336, 364, 392, 420, 448, 476, 504, 532, 560, 588, 616, 644, 672, 700, 728, . . .

The multipliers of 50 are: 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, . . .

The multipliers of 70 are: 70, 140, 210, 280, 350, 420, 490, 560, 630, 700, 770, . . .

The multipliers of 140 are: 140, 280, 420, 560, 700, 840, . . .

We can see that:

LCM( 28, 50, 70, 140 ) = 700