[2,7]
The natural numbers are the positive integers starting from 1. In the set of numbers from -10 to 10 inclusive, the natural numbers are 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Therefore, there are 10 natural numbers in that set.
There are 90 two-digit numbers in the set of natural numbers. These numbers range from 10 to 99, inclusive. To find the total, you can subtract the smallest two-digit number (10) from the largest (99) and add one: (99 - 10 + 1 = 90).
It would appear that these are a selection of numbers from Z, the set of integers - written without any separators.
11
Exactly 50
The natural numbers are the positive integers starting from 1. In the set of numbers from -10 to 10 inclusive, the natural numbers are 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. Therefore, there are 10 natural numbers in that set.
[2,7] the bracket means inclusive but if it said exclusive it would have parenthesis replacing the brackets.
There are 90 two-digit numbers in the set of natural numbers. These numbers range from 10 to 99, inclusive. To find the total, you can subtract the smallest two-digit number (10) from the largest (99) and add one: (99 - 10 + 1 = 90).
The set of even numbers is the set of all the numbers that are divisible by 2 (or multiples of 2).
All of the odd numbers between 11 and 99 inclusive are two digit numbers that are not multiples of 2. There are 45 of them.
It would appear that these are a selection of numbers from Z, the set of integers - written without any separators.
11
Seven of them.
Exactly 50
There are 48/2 + 1 = 25 odd numbers in 1 to 49, inclusive.
Some examples of sets of real numbers include: The set of positive integers: {1, 2, 3, 4, ...} The set of rational numbers: {1/2, -3/4, 5/6, ...} The set of whole numbers: {..., -2, -1, 0, 1, 2, ...} The set of natural numbers: {0, 1, 2, 3, 4, ...} The set of irrational numbers: {√2, π, e, ...}
between 1 and 600 inclusive there are:300 numbers divisible by 2200 numbers divisible by 3100 numbers divisible by both 2 and 3400 numbers divisible by 2 or 3.