## How to find the Least Common Multiple of 42 and 55?

On this page below, we'll use the Prime Factorisation, and the List of Multiples method to find out the LCM of 42 and 55.

Follow the steps below, and let's calculate the LCM of 42 and 55.

### Method 1 - Prime factorization

#### Step 1: Create a list of all the prime factors of the numbers 42 and 55:

##### Prime factors of 42

The prime factors of 42 are 2, 3 and 7. Prime factorization of 42 in exponential form is:

42 = 21x31x71

##### Prime factors of 55

The prime factors of 55 are 5 and 11. Prime factorization of 55 in exponential form is:

55 = 51x111

#### Step 2: Identify the highest power of each prime number from the above boxes:

21, 31, 71, 51, 111

#### Step 3: Multiply these values together:

21x31x71x51x111=2310

#### Step 4: The result:

As seen on the calculation above, we have now obtained the LCM of 42 and 55.

The Least Common Multiple of 42 and 55 is 2310.

### Method 2 - List of Multiples

Find and list multiples of each number until the first common multiple is found. This is the lowest common multiple.

#### Multiples of 42:

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, 2394, 2436

#### Multiples of 55:

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, 2420, 2475

#### Therefore,

LCM(42, 55) = 2310