Last updated on May 26th, 2025
The LCM is the smallest number which can be exactly divisible by each of the numbers. It can also be defined as the least number, which is a common multiple of all numbers. LCM helps in scheduling, also used in traffic light mechanisms, etc
The LCM of 42 and 66 is 462. We can get the exact value of LCM of 42 and 66 through various methods. Let us see how.
To find the LCM of 42 and 66 we will learn some methods:
Listing Multiples method is one of the methods used to find LCM of some given numbers. We have to know the multiples of the given numbers and then apply this method.
Step 1:List down the multiples of each number
Multiples of 42 = 42,84,126,168,210,252,294,336,378,420,462,504,.....
Multiples of 66= 66,132,198,264,330,396,462,528,594,....
Step 2: Find out the smallest multiple from the listed multiple
The smallest common multiple is 462
Thus, LCM (42,66) = 462.
Rule: The prime factorization of each number is to be done, and then the highest power of the prime factors are multiplied to get the LCM.
Step 1: Find the prime factorization of the numbers:
Prime factorization of 42 = 2×3×7
Prime factorization of 66 = 2×3×11
Step 1:Take the highest powers of each prime factor, and multiply the highest powers to
get the LCM:
2×3×7×11 = 462
LCM (42,66) = 462.
This is the most used method to find any LCM. It involves dividing both numbers 42 and 66 by their common prime factors until no further division is possible, then multiplying the divisors to find the LCM
Step 1: Write the numbers, divide by common prime factors. A prime integer that is evenly divisible into at least one of the provided numbers should be used to divide the row of numbers.
The first common prime divisors for both 42 and 66 are 2 and 3. We choose 2.
Step 2: Dividing 42 and 66 with 2, we get 21 and 33 respectively.
Step 3: Repeat Step 1 and 2 till both are getting perfectly divided. Continue dividing the numbers until the last row of the results is ‘1’ and bring down the numbers not divisible by the previously chosen prime number.
2×3×7×11 = 462
Thus, LCM (42,66) = 462
Misconception is normal, but we should avoid it whenever we are solving math problems. Let us see how can we avoid some common errors.
The LCM of two numbers is 462 and the numbers are in the ratio 7:11. Find the numbers.
Since, the numbers are in the ratio 7:11, so let the numbers 7x and 11x.
LCM of 7x and 11x → 77x.
Now, 77x=462
⇒ x= 462/77
⇒ x = 6
So, the numbers are 7×6 = 42 and 11×6=66.
Answer: 42 and 66
Expanded the ratio and assumed the numbers to be 7x and 11x. We know that their ratio is equal to the given ratio 462. Hence, solved the equation for that.
LCM (42,66) = x. Find the smallest positive integer (n), where n×x=231.
LCM (42,66) = x
We know that the LCM of 42 and 66 from the previous calculations.
LCM (42,66) = 462
n×462=231
⇒ n= 231/462
⇒ n = 1/2
Answer: 1/2
We made use of the LCM OF 42 and 66 and solved the equation to get the value of n.
What is the LCM of 12 and 18?
Prime Factorization of 12 =22×3
Prime Factorization of 18 =2×32
LCM(12,18)= 22×32 =36
Answer: 36
The LCM of numbers 12 and 18 are found using the Prime factorization method.
Hiralee Lalitkumar Makwana has almost two years of teaching experience. She is a number ninja as she loves numbers. Her interest in numbers can be seen in the way she cracks math puzzles and hidden patterns.
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