Find the number of positive integers not exceeding 1000
that are divisible by 3 but not by 4.
Every third number is divisible by 3.
. . There are: . numbers divisible by 3.
But every twelfth number is divisible by 3 and by 4.
. . There are: . multiples of 3 which are divisible by 4.
Therefore, there are: . such numbers.