20 and 112
25 and 50
20, 50, 60 and 70
No because they are composite numbers having more than two factors
If the two numbers are relatively prime, their least common multiple is their product. The prime factors of 99 are 3, 3, and 11. Since the two numbers are relatively prime, the possibilities are 9 and 11 or 1 and 99. The pair of 9 and 11 add up to 20 and their least common multiple is 99. So, 9 and 11 are the two numbers.
The prime factors of 20 are 2x2x5.
The prime numbers of 20 are 2, 2 and 5. (2*2*5 = 20)
The prime numbers between 20 and 30 are 23 and 29.
No because they are composite numbers having more than two factors
These are the prime numbers 1-20 2,3,5,7,11,13,17,19
The GCF of 9 and 20 is 1. One way to determine the greatest common factor is to find all the factors of the numbers and compare them. The factors of 9 are 1, 3, and 9. The factors of 20 are 1, 2, 4, 5, 10, and 20. The only common factor is 1. Therefore, the greatest common factor is 1, which means the numbers are relatively prime. The greatest common factor can also be calculated by identifying the common prime factors and multiplying them together. The prime factors of 9 are 3 and 3. The prime factors of 20 are 2, 2, and 5. There are no prime factors in common, so the numbers are relatively prime, which means the greatest common factor is 1. Another way to approach this is to look at the difference between 9 and 20, which is 11. The greatest common factor of two numbers cannot be larger than the difference between the two numbers and must be a factor of the difference. Since 11 is a prime number, the greatest common factor must be either 1 or 11. The numbers 9 and 20 are not divisible by 11, so the greatest common factor must be 1.
If the two numbers are relatively prime, their least common multiple is their product. The prime factors of 99 are 3, 3, and 11. Since the two numbers are relatively prime, the possibilities are 9 and 11 or 1 and 99. The pair of 9 and 11 add up to 20 and their least common multiple is 99. So, 9 and 11 are the two numbers.
2/5 of the numbers from 1 to 20 are prime numbers
The easiest way to do this is to split the numbers down into their prime factors: 14 = 2x7 20 = 2x2x5 The next step is to spot any common prime factors. In this case both numbers have a 2 as a prime factor. Therefore, the HCF of 14 and 20 is 2.
The prime factors of 20 are 2x2x5.
10 and 20 are composite numbers, not prime numbers. The prime factorization of 10 is 2 x 5. The prime factorization of 20 is 2 x 2 x 5.
The LCM of these numbers is 740. LCM is Least Common Multiple.
The prime numbers of 20 are 2, 2 and 5. (2*2*5 = 20)
The only even prime number is 2. It happens twice in the prime factorization of 20.
The prime numbers between 20 and 30 are 23 and 29.