30, 60 or 90
Any multiple of 10.
All of the composite numbers less than 100 have factor pairs.
3,7,11,19,23,31,43,47,51,59,67,71,79...
2 and 7 are prime numbers less than 10 that are factors of 42 and 70.
Yes.
Any multiple of 10.
4 and 6 6 and 8 Any time the two numbers have a common factor, their LCM will be less than the product because the common factor contributes to the LCM fewer times than it contributes to the product.
None. You can't have an LCM less than a GCF.
All of the composite numbers less than 100 have factor pairs.
Any factor of the number less than the number itself.
48 and 36
No. A common multiple is a multiple of both numbers. There is no multiple of 17 that is less than 17.
Numbers less than 100 having 19 as a factor are 19, 38, 57, 76, and 95.
3,7,11,19,23,31,43,47,51,59,67,71,79...
43 is the prime you seek. This question is really easy if you know that even numbers larger than 2 are not prime, and that any number ending in 5 is a multiple. The integers greater than 41 and less than 47 are 42,43,44,45, and 46. 42,44,46 are even and 45 is a multiple of 5. Thus 43 is the only candidate. If it factors, is has a prime factor less than 7 since 7 X 7 = 49 and 49 > 43. 2 is not a factor since 43 is odd. 3 is not a factor is the sum of its digits is 7 which is not a multiple of 3. 5 is not a factor since it does not end in 5 .
2 and 7 are prime numbers less than 10 that are factors of 42 and 70.
3,9,27,81,243,729