No. If they are even numbers and not 2, they are not prime. 20 is divisible by 1, 2, 4, 5, 20, and 20. 18 is divisible by 1, 2, 3, 6, 9, and 18.
No. The fraction 18/20 can be simplified to 9/10, because both 18 and 20 are divisible by two.
numbers between 10 and 20 is divisible by both 4 and 6 = 12 & 18
5
18 is not divisible by 5 and 7.
138 is not divisible by 18.
-- Neither 2 nor 5 is divisible by 18. -- 18 is divisible by 2, but not by 5.
20 over 72.[divide by 4]5 over 18[5 is prime, 18 is not divisible by 5; no further simplification possible]
All multiples of 18 are divisible by 9. Not all multiples of 9 are divisible by 18.
12, 14, 16, 18, 20
2 4 6 8 10 12 14 16 18 20
6 12 18