LCM( 55, 42, 33 ) = 2310
Write down multiples of each number until you find the first common multiple:
The multipliers of 55 are: 55, 110, 165, 220, 275, 330, 385, 440, 495, 550, 605, 660, 715, 770, 825, 880, 935, 990, 1045, 1100, 1155, 1210, 1265, 1320, 1375, 1430, 1485, 1540, 1595, 1650, 1705, 1760, 1815, 1870, 1925, 1980, 2035, 2090, 2145, 2200, 2255, 2310, 2365, . . .
The multipliers of 42 are: 42, 84, 126, 168, 210, 252, 294, 336, 378, 420, 462, 504, 546, 588, 630, 672, 714, 756, 798, 840, 882, 924, 966, 1008, 1050, 1092, 1134, 1176, 1218, 1260, 1302, 1344, 1386, 1428, 1470, 1512, 1554, 1596, 1638, 1680, 1722, 1764, 1806, 1848, 1890, 1932, 1974, 2016, 2058, 2100, 2142, 2184, 2226, 2268, 2310, 2352, . . .
The multipliers of 33 are: 33, 66, 99, 132, 165, 198, 231, 264, 297, 330, 363, 396, 429, 462, 495, 528, 561, 594, 627, 660, 693, 726, 759, 792, 825, 858, 891, 924, 957, 990, 1023, 1056, 1089, 1122, 1155, 1188, 1221, 1254, 1287, 1320, 1353, 1386, 1419, 1452, 1485, 1518, 1551, 1584, 1617, 1650, 1683, 1716, 1749, 1782, 1815, 1848, 1881, 1914, 1947, 1980, 2013, 2046, 2079, 2112, 2145, 2178, 2211, 2244, 2277, 2310, 2343, . . .
We can see that:
LCM( 55, 42, 33 ) = 2310
This solution can be visualized using a Venn diagram.
The LCM is equal to the product of all the numbers on the diagram.