C语言的文件输出问题

预计输出“13 15 17 19 19”
但运行后输出为“3 3 3 3 3”
是哪里出问题了？

#include<stdio.h>
#include<stdlib.h>
int main()
{
    int i,n;
    FILE *fp;
    if((fp=fopen("temp","w+"))==NULL)
    {
        printf("can not set temp file\n");
        exit(0);
    }
    for(i=1;i<=10;i++)
        fprintf(fp,"%3d",i);
    for(i=0;i<10;i++)
    {
        fseek(fp,i*3L,0);
        fscanf(fp,"%d",&n);
        fseek(fp,i*3L,0);
        fprintf(fp,"3d",n+10);
    }
    for(i=1;i<=5;i++)
    {
        fseek(fp,i*6L,0);
        fscanf(fp,"%d",&n);
        printf("%3d",n);
    }
    fclose(fp);
    return 0;
}

19行 修改，缺少 %

#include<stdio.h>
#include<stdlib.h>
int main()
{
    int i,n;
    FILE *fp;
    if((fp=fopen("temp","w+"))==NULL)
    {
        printf("can not set temp file\n");
        exit(0);
    }
    for(i=1;i<=10;i++)
        fprintf(fp,"%3d",i);
    for(i=0;i<10;i++)
    {
        fseek(fp,i*3L,0);
        fscanf(fp,"%d",&n);
        fseek(fp,i*3L,0);
        fprintf(fp,"%3d",n+10); // 修改，缺少 %
    }
    for(i=1;i<=5;i++)
    {
        fseek(fp,i*6L,0);
        fscanf(fp,"%d",&n);
        printf("%3d",n);
    }
    fclose(fp);
    return 0;
}