Question

If S is the set of positive integers from 1 to 100 inclusive, which of the following is true?

S contains more 1-digit numbers than 2-digit numbers.
S contains more numbers with units digit 0 than with units digit 9.
S contains more multiples of 5 than multiples of 10.
S contains more multiples of 8 than multiples of 2.
S contains more even numbers than odd numbers

Answer 1

S contains more multiples of 5 than multiples of 10.

Answer 2

obviously can't have more 1 digit numbers: 1-9 are the only one digit, 10-99 are all two digit.

Can't have more numbers with 0 in them. Only 10,20,30... etc. have those. (10 numbers)
But there is 9,19,29,39,49,59,69,79,89,90,99 (more than 10)

It DOES have more multiples of 5. Again, list them:

5-10-15-20... etc.
Multiples of 10 are only 10-100, which is less.

Obviously not more multiples of 8 than 2, that doesn't make sense at all.

More even numbers than odd... well, from 1-100 inclusive, there would be 50 even and 50 odd numbers. So no.

Only 3 is right.

Answer 3

double check me, im not 100%