81, 84, 87.
3,6,9,12,15,18,21,24,27
1, 2, 3, 4
15, 30 and 45
81 84 87
6, 12, 18, 24, 30 & 36.
3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39
3. All other multiples of 3 are not prime.
81, 84, 87.
33
To find numbers that are multiples of both 3 and 5, we need to find the numbers that are common multiples of both 3 and 5. These are numbers that are divisible by the least common multiple of 3 and 5, which is 15. The first four numbers less than 70 that are multiples of both 3 and 5 are 15, 30, 45, and 60.
It is less than -3.
Here are all 13 of them: 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165, 180, 195
3,6,9,12,15,18,21,24,27
81,84,87,90
There are 3 such numbers: 30, 60, 90.
3, 9, and 15. 6 and 18 are also multiples of 3, but are even.