Question

How many integers between 1-100 are divisible by 3?

Answer 1

You can state the qurstion in an other way
how many integers between 1-100 has 3 in their prime compostion or how many many numbers can be written as 3*a where a is any number
the multiplication table of 3 shows that 3*33=99
which means that highest product below 100 is 3*33
so there are 33 numbers that are divisible by three

Answer 2

They are 17 odd numbers.