# 10, 15 and 20 LCM

LCM of 10, 15 and 20 is equal to 60. The comprehensive work provides more insight of how to find what is the lcm of 10, 15 and 20 by using prime factors and special division methods, and the example use case of mathematics and real world problems.

__what is the lcm of 10, 15 and 20?__

lcm (10 15 20) = (?)

10 => 2 x 5

15 => 3 x 5

20 => 2 x 2 x 5

= 2 x 5 x 3 x 2

= 60

lcm (10, 15 and 20) = 60

60 is the lcm of 10, 15 and 20.

__where,__

10 is a positive integer,

15 is a positive integer,

60 is the lcm of 10, 15 and 20,

{2, 5} in {2 x 5, 3 x 5, 2 x 2 x 5} are the most repeated factors of 10, 15 and 20,

{3, 2} in {2 x 5, 3 x 5, 2 x 2 x 5} are the the other remaining factors of 10, 15 and 20.

__Use in Mathematics: LCM of 10, 15 and 20__

The below are some of the mathematical applications where lcm of 10, 15 and 20 can be used:

- to find the least number which is exactly divisible by 10, 15 and 20.
- to find the common denominators for the fractions having 10, 15 and 20 as denominators in the unlike fractions addition or subtraction.

__Use in Real-world Problems: 10, 15 and 20 lcm__In the context of lcm real world problems, the lcm of 10, 15 and 20 helps to find the exact time when three similar and recurring with different time schedule happens together at the same time. For example, the real world problems involve lcm in situations to find at what time all the bells A, B and C toll together, if bell A tolls at 10 seconds, B tolls at 15 seconds and C tolls at 20 seconds repeatedly. The answer is that all bells A, B and C toll together at 60 seconds for the first time, at 120 seconds for the second time, at 180 seconds for the third time and so on.

__Important Notes: 10, 15 and 20 lcm__The below are the important notes to be remembered while solving the lcm of 10, 15 and 20:

- The repeated and non-repeated prime factors of 10, 15 and 20 should be multiplied to find the least common multiple of 10, 15 and 20, when solving lcm by using prime factors method.
- The results of lcm of 10, 15 and 20 is identical even if we change the order of given numbers in the lcm calculation, it means the order of given numbers in the lcm calculation doesn't affect the results.

## How-to: What is the LCM of 10, 15 and 20?

__Solved example using prime factors method:__

What is the LCM of 10, 15 and 20?

step 1 Address the input parameters, values and observe what to be found:

__Input parameters and values:__

A = 10

B = 15

C = 20

__What to be found:__

find the lcm of 10, 15 and 20

step 2 Find the prime factors of 10, 15 and 20:

Prime factors of 10 = 2 x 5

Prime factors of 15 = 3 x 5

Prime factors of 20 = 2 x 2 x 5

step 3 Identify the repeated and non-repeated prime factors of 10, 15 and 20:

{2, 5} are the most repeated factors and {3, 2} are the non-repeated factors of 10, 15 and 20.

step 4 Find the product of repeated and non-repeated prime factors of 10, 15 and 20:

= 2 x 5 x 3 x 2

= 60

lcm(20 and 30) = 60

Hence,

lcm of 10, 15 and 20 is 60

__Solved example using special division method:__

This special division method is the easiest way to understand the entire calculation of what is the lcm of 10, 15 and 20.

step 1 Address the input parameters, values and observe what to be found:

__Input parameters and values:__

Integers: 10, 15 and 20

__What to be found:__

lcm (10, 15, 20) = ?

step 2 Arrange the given integers in the horizontal form with space or comma separated format:

10, 15 and 20

step 3 Choose the divisor which divides each or most of the given integers (10, 15 and 20), divide each integers separately and write down the quotient in the next line right under the respective integers. Bring down the integer to the next line if any integer in 10, 15 and 20 is not divisible by the selected divisor; repeat the same process until all the integers are brought to 1 as like below:

2 | 10 | 15 | 20 |

2 | 5 | 15 | 10 |

3 | 5 | 15 | 5 |

5 | 5 | 5 | 5 |

1 | 1 | 1 |

step 4 Multiply the divisors to find the lcm of 10, 15 and 20:

= 2 x 2 x 3 x 5

= 60

LCM(10, 15, 20) = 60

The least common multiple for three numbers 10, 15 and 20 is 60