Error comes out with precision, how can I get rid from this? [duplicate]

Answer comes wrong when using decimal places!

I'm running the following program:

#include<stdio.h>

#include<math.h>

main()

{

float x,y,div;

printf("Enter two numbers x,y \n");

scanf("%f%f",&x, &y);

div=x/y;

printf("div=%12.10f\n",div;

return 0;

}

After running, when I put x=1 and y=3 then answer comes 0.3333333433, but answer should be 0.3333333333. Why this error comes ? How can I get rid from this kind of error ? Please help.