Are there as many integers as even integers?

There are a number of different senses in which one might discuss the "size" of a set of numbers. One sense is cardinality, as referred to by Adam Waggoner and Mark Harrison. read more

2) There are at most as many integers as there are positive integers, because for every integer you can uniquely find a positive integer (and also recover the integer). For this, let's do a map: Negative integers n go to odd positive integers under the mapping n -> 2*(-n)-1. read more

There are just as many as there are numbers divisible by $5$ from $4$ to $203$, which is the same as the number of numbers divisible by $5$ from $5$ to $200$, which is the same as the number of integers from $1$ to $40$, which is $40$. read more

Notice that we are told that r and s are integers. (1) s – r = 10 --> since r and s are integers and s – r = 10 then there will be 9 integers between them. For example take s=10 and r=0, then there are following integers between them: 1, 2, 3, 4, 5, 6, 7, 8, and 9. read more