In natural numbers 1,2,3,..., 1000, how many are multiples of 2 and 3, but not multiples of 5?

In natural numbers 1,2,3,..., 1000, how many are multiples of 2 and 3, but not multiples of 5?

The least common multiple of 2 and 3 is 61000, and the multiples of 6 are: 1000 △ 6 ≈ 166 (pieces)
The least common multiple of 2, 3 and 5 is 3010000, and the multiples of 30 are: 1000 △ 30 ≈ 33 (pieces)
So the numbers that meet the conditions are: 166-33 = 133
If you don't understand, you are welcome to ask,

At least how many numbers from 1 to 100 can guarantee that one of them is a multiple of the other

Take at least 51 numbers, because it is impossible to divide more than 50 numbers. That is to say, there must be 1, 2, 3, 4. Until 49. That is to say, if you are not lucky, the first 50 numbers you take are 51, 52, until 100. There can be no integral division between them. You must take another number between 1 and 50. So it is 51

The Mathematical Olympiad problem takes out two different numbers from the 100 numbers from 1 to 100, and the sum of the numbers is a multiple of 5. How many kinds of methods are there?
It's better to have a process

The way of thinking upstairs is very correct, but the answer is wrong. There are 20 * 19 / 2 = 190 that can divide 5. That is to say, it should be the combination number rather than the permutation number, so the final result should be 1180-190 = 990

1. Find the rule and fill in the brackets: 1,3,7,13, () 2. Write the following four related formulas into a comprehensive formula, which is 25 + 27 = 52
256-56 = 200 200 divided by 8 = 25 2 times 4 = 8

1. Find the rule and fill in the numbers in brackets: 1,3,7,13, (21)
2. Write the following four related formulas into a comprehensive formula, which is 25 + 27 = 52 256-56 = 200 200 divided by 8 = 25 2 multiplied by 4 = 8
（256-56）÷（2×4）+27=52