Created By : Jatin Gogia
Reviewed By : Rajasekhar Valipishetty
Last Updated : Apr 06, 2023
Free LCM Calculator determines the least common multiple (LCM) between 42 and 47 the smallest integer that is 1974 that is divisible by both numbers.
Least Common Multiple (LCM) of 42 and 47 is 1974.
LCM(42,47) = 1974
Least common multiple or lowest common denominator (LCD) can be calculated in three ways;
Least common multiple can be found by multiplying the highest exponent prime factors of 42 and 47. First we will calculate the prime factors of 42 and 47.
Prime Factorization of 42
2 | 42 |
3 | 21 |
7 | 7 |
1 |
Prime factors of 42 are 2, 3,7. Prime factorization of 42 in exponential form is:
42 = 21×31×71
Prime Factorization of 47
47 | 47 |
1 |
Prime factors of 47 are 47. Prime factorization of 47 in exponential form is:
47 = 471
Now multiplying the highest exponent prime factors to calculate the LCM of 42 and 47.
LCM(42,47) = 21×31×71×471
LCM(42,47) = 1974
Factors of 42
List of positive integer factors of 42 that divides 42 without a remainder.
1, 2, 3, 6, 7, 14, 21, 42
Factors of 47
List of positive integer factors of 47 that divides 47 without a remainder.
1, 47
The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 42 and 47, than apply into the LCM equation.
GCF(42,47) = 1
LCM(42,47) = ( 42 × 47) / 1
LCM(42,47) = 1974 / 1
LCM(42,47) = 1974
(i) The LCM of 47 and 42 is associative
LCM of 42 and 47 = LCM of 47 and 42
1. What is the LCM of 42 and 47?
Answer: LCM of 42 and 47 is 1974.
2. What are the Factors of 42?
Answer: Factors of 42 are 1, 2, 3, 6, 7, 14, 21, 42. There are 8 integers that are factors of 42. The greatest factor of 42 is 42.
3. What are the Factors of 47?
Answer: Factors of 47 are 1, 47. There are 2 integers that are factors of 47. The greatest factor of 47 is 47.
4. How to Find the LCM of 42 and 47?
Answer:
Least Common Multiple of 42 and 47 = 1974
Step 1: Find the prime factorization of 42
42 = 2 x 3 x 7
Step 2: Find the prime factorization of 47
47 = 47
Step 3: Multiply each factor the greater number of times it occurs in steps i) or ii) above to find the lcm:
LCM = 1974 = 2 x 3 x 7 x 47
Step 4: Therefore, the least common multiple of 42 and 47 is 1974.