The sum of all natural numbers less than 200, that are  divisible neither by 3 nor by 5, is

The required sum.=(1+2+3+…+199)−(3+6+9+…+198)−(5+10+15+…+195)+(15+30+45+…+195)=1992(1+199)−662(3+198)−392(5+195)+132(15+195)=199×100−33×201−39×100+13×105=10732