#include <stdio.h>

int main(void) {
	int a[100];
	for (int i = 0; i < 100; i++)
		a[i] = i;
		
	int sum = 0;
	int start = 10, end = 40;
	
	for (int i = start; i <= end; i++)
		sum += a[i];
	
	printf("Sum from a[%d] to a[%d] is: %d\n", start, end, sum);
	printf("Average from a[%d] to a[%d] is: %g\n", start, end, (float)(sum) / (float)(end - start + 1));
	
	return 0;
}