C How to calculate a percentage(perthousands) without floating point precision

Question

How do you calculate a percentage from 2 int values into a int value that represents a percentage(perthousands for more accuracy)?

Background/purpose: using a processor that doesn't have a FPU, floating point computations take 100's of times longer.

int x = 25;
int y = 75;
int resultPercentage; // desire is 250 which would mean 25.0 percent

resultPercentage = (x/(x+y))*1000; // used 1000 instead of 100 for accuracy
printf("Result= ");
printf(resultPercentage);

output:

Result= 0

When really what I need is 250. and I can't use ANY Floating point computation.

Example of normal fpu computation:

int x = 25;
int y = 75;
int resultPercentage; // desire is 250 which would mean 25.0 percent

resultPercentage = (int)( ( ((double)x)/(double(x+y)) ) *1000); //Uses FPU slow

printf("Result= ");
printf(resultPercentage);

output:

Result= 250

But the output came at the cost of using floating point computations.