LCM of 20 and 155
620 is the LCM of 20 and 155. 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 20 and 155, provided along with the use cases of mathematics and real-world problems.
what is the lcm of 20 and 155?
lcm (20 155) = (?)
20 => 2 x 2 x 5
155 => 5 x 31
= 5 x 2 x 2 x 31
= 620
lcm (20 and 155) = 620
620 is the LCM of 20 and 155.
where,
20 is a positive integer,
155 is a positive integer,
620 is the LCM of 20 and 155,
{5} in {2 x 2 x 5, 5 x 31} is the common factors of 20 and 155,
{2 x 2 x 31} in {2 x 2 x 5, 5 x 31} are the uncommon factors of 20 and 155.
Use in Mathematics: LCM of 20 and 155
The below are some of the mathematical applications where lcm of 20 and 155 can be used:
- to find the least number which is exactly divisible by 20 and 155.
- to find the common denominator for two fractions having 20 and 155 as denominators in the unlike fractions addition or subtraction.
In the context of lcm real world problems, the lcm of 20 and 155 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 20 seconds and bell B tolls at 155 seconds repeatedly. The answer is that all bells A and B toll together at 620 seconds for the first time, at 1240 seconds for the second time, at 1860 seconds for the third time and so on.
Important Notes: 20 and 155 lcm
The below are the important notes to be remembered while solving the lcm of 20 and 155:
- The common prime factors and the remaining prime factors of 20 and 155 should be multiplied to find the least common multiple of 20 and 155, when solving lcm by using prime factors method.
- The results of lcm of 20 and 155, and the lcm of 155 and 20 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 20 and 155?
The below solved example with step by step work shows how to find what is the lcm of 20 and 155 by using prime factors method and division method.
Solved example using prime factors method:
What is the LCM of 20 and 155?
step 1
Address the input parameters, values and observe what to be found:
Input parameters and values:
A = 20
B = 155
What to be found:
find the lcm of 20 and 155
step 2 Find the prime factors of 20 and 155:
Prime factors of 20 = 2 x 2 x 5
Prime factors of 155 = 5 x 31
step 3 Identify the repeated and non-repeated prime factors of 20 and 155:
{5} is the most repeated factor and {2 x 2 x 31} are the non-repeated factors of 20 and 155.
step 4 Find the product of repeated and non-repeated prime factors of 20 and 155:
= 5 x 2 x 2 x 31
= 620
lcm(20 and 155) = 620
Hence,
lcm of 20 and 155 is 620
This special division method is one of the easiest ways to understand the entire calculation to find the LCM of 20 and 155.
step 1 Address the input parameters, values and observe what to be found:
Input parameters and values:
Integers: 20 and 155
What to be found:
lcm (20, 155) = ?
step 2 Arrange the given integers in the horizontal form with space or comma separated format:
20 and 155
step 3 Choose the divisor which divides each or most of the given integers (20 and 155), 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 20 and 155 is not divisible by the selected divisor; repeat the same process until all the integers are brought to 1 as like below:
| 2 | 20 | 155 |
| 2 | 10 | 155 |
| 5 | 5 | 155 |
| 31 | 1 | 31 |
| 1 | 1 |
step 4 Multiply the divisors to find the lcm of 20 and 155:
= 2 x 2 x 5 x 31
= 620
LCM(20, 155) = 620
The LCM of two numbers 20 and 155 is 620