LCM of 42 and 129
1806 is the LCM of 42 and 129. The step-by-step solution using prime factors and special division methods is one of the simple methods to easily understand how to find what is the LCM of 42 and 129, provided along with the use cases of mathematics and real-world problems.
what is the lcm of 42 and 129?
lcm (42 129) = (?)
42 => 2 x 3 x 7
129 => 3 x 43
= 3 x 2 x 7 x 43
= 1806
lcm (42 and 129) = 1806
1806 is the LCM of 42 and 129.
where,
42 is a positive integer,
129 is a positive integer,
1806 is the LCM of 42 and 129,
{3} in {2 x 3 x 7, 3 x 43} is the common factors of 42 and 129,
{2 x 7 x 43} in {2 x 3 x 7, 3 x 43} are the uncommon factors of 42 and 129.
Use in Mathematics: LCM of 42 and 129
The below are some of the mathematical applications where lcm of 42 and 129 can be used:
- to find the least number which is exactly divisible by 42 and 129.
- to find the common denominator for two fractions having 42 and 129 as denominators in the unlike fractions addition or subtraction.
In the context of lcm real world problems, the lcm of 42 and 129 helps to find the exact time when two similar and recurring events 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 the bells A and B all toll together, if bell A tolls at 42 seconds and bell B tolls at 129 seconds repeatedly. The answer is that all bells A and B toll together at 1806 seconds for the first time, at 3612 seconds for the second time, at 5418 seconds for the third time and so on.
Important Notes: 42 and 129 lcm
The below are the important notes to be remembered while solving the lcm of 42 and 129:
- The common prime factors and the remaining prime factors of 42 and 129 should be multiplied to find the least common multiple of 42 and 129, when solving lcm by using prime factors method.
- The results of lcm of 42 and 129, and the lcm of 129 and 42 are identical, it means the order of given numbers in the lcm calculation doesn't affect the results.
How-to: What is the LCM of 42 and 129?
The below solved example with step by step work shows how to find what is the lcm of 42 and 129 by using prime factors method and division method.
Solved example using prime factors method:
What is the LCM of 42 and 129?
step 1
Address the input parameters, values and observe what to be found:
Input parameters and values:
A = 42
B = 129
What to be found:
find the lcm of 42 and 129
step 2 Find the prime factors of 42 and 129:
Prime factors of 42 = 2 x 3 x 7
Prime factors of 129 = 3 x 43
step 3 Identify the repeated and non-repeated prime factors of 42 and 129:
{3} is the most repeated factor and {2 x 7 x 43} are the non-repeated factors of 42 and 129.
step 4 Find the product of repeated and non-repeated prime factors of 42 and 129:
= 3 x 2 x 7 x 43
= 1806
lcm(42 and 129) = 1806
Hence,
lcm of 42 and 129 is 1806
This special division method is one of the easiest ways to understand the entire calculation to find the LCM of 42 and 129.
step 1 Address the input parameters, values and observe what to be found:
Input parameters and values:
Integers: 42 and 129
What to be found:
lcm (42, 129) = ?
step 2 Arrange the given integers in the horizontal form with space or comma separated format:
42 and 129
step 3 Choose the divisor which divides each or most of the given integers (42 and 129), 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 42 and 129 is not divisible by the selected divisor; repeat the same process until all the integers are brought to 1 as like below:
| 2 | 42 | 129 |
| 3 | 21 | 129 |
| 7 | 7 | 43 |
| 43 | 1 | 43 |
| 1 | 1 |
step 4 Multiply the divisors to find the lcm of 42 and 129:
= 2 x 3 x 7 x 43
= 1806
LCM(42, 129) = 1806
The LCM of two numbers 42 and 129 is 1806