# 15, 45 and 75 LCM

LCM of 15, 45 and 75 is equal to 225. The comprehensive work provides more insight of how to find what is the lcm of 15, 45 and 75 by using prime factors and special division methods, and the example use case of mathematics and real world problems.

__what is the lcm of 15, 45 and 75?__

lcm (15 45 75) = (?)

15 => 3 x 5

45 => 3 x 3 x 5

75 => 3 x 5 x 5

= 3 x 5 x 3 x 5

= 225

lcm (15, 45 and 75) = 225

225 is the lcm of 15, 45 and 75.

__where,__

15 is a positive integer,

45 is a positive integer,

225 is the lcm of 15, 45 and 75,

{3, 5} in {3 x 5, 3 x 3 x 5, 3 x 5 x 5} are the most repeated factors of 15, 45 and 75,

{3, 5} in {3 x 5, 3 x 3 x 5, 3 x 5 x 5} are the the other remaining factors of 15, 45 and 75.

__Use in Mathematics: LCM of 15, 45 and 75__

The below are some of the mathematical applications where lcm of 15, 45 and 75 can be used:

- to find the least number which is exactly divisible by 15, 45 and 75.
- to find the common denominators for the fractions having 15, 45 and 75 as denominators in the unlike fractions addition or subtraction.

__Use in Real-world Problems: 15, 45 and 75 lcm__In the context of lcm real world problems, the lcm of 15, 45 and 75 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 15 seconds, B tolls at 45 seconds and C tolls at 75 seconds repeatedly. The answer is that all bells A, B and C toll together at 225 seconds for the first time, at 450 seconds for the second time, at 675 seconds for the third time and so on.

__Important Notes: 15, 45 and 75 lcm__The below are the important notes to be remembered while solving the lcm of 15, 45 and 75:

- The repeated and non-repeated prime factors of 15, 45 and 75 should be multiplied to find the least common multiple of 15, 45 and 75, when solving lcm by using prime factors method.
- The results of lcm of 15, 45 and 75 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 15, 45 and 75?

__Solved example using prime factors method:__

What is the LCM of 15, 45 and 75?

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

__Input parameters and values:__

A = 15

B = 45

C = 75

__What to be found:__

find the lcm of 15, 45 and 75

step 2 Find the prime factors of 15, 45 and 75:

Prime factors of 15 = 3 x 5

Prime factors of 45 = 3 x 3 x 5

Prime factors of 75 = 3 x 5 x 5

step 3 Identify the repeated and non-repeated prime factors of 15, 45 and 75:

{3, 5} are the most repeated factors and {3, 5} are the non-repeated factors of 15, 45 and 75.

step 4 Find the product of repeated and non-repeated prime factors of 15, 45 and 75:

= 3 x 5 x 3 x 5

= 225

lcm(20 and 30) = 225

Hence,

lcm of 15, 45 and 75 is 225

__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 15, 45 and 75.

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

__Input parameters and values:__

Integers: 15, 45 and 75

__What to be found:__

lcm (15, 45, 75) = ?

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

15, 45 and 75

step 3 Choose the divisor which divides each or most of the given integers (15, 45 and 75), 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 15, 45 and 75 is not divisible by the selected divisor; repeat the same process until all the integers are brought to 1 as like below:

3 | 15 | 45 | 75 |

3 | 5 | 15 | 25 |

5 | 5 | 5 | 25 |

5 | 1 | 1 | 5 |

1 | 1 | 1 |

step 4 Multiply the divisors to find the lcm of 15, 45 and 75:

= 3 x 3 x 5 x 5

= 225

LCM(15, 45, 75) = 225

The least common multiple for three numbers 15, 45 and 75 is 225