C语言基础：简单的数学运算的代码

如下资料是关于C语言基础：简单的数学运算的内容。
#include <stdio.h>

int main ()
{
int seconds_in_an_hour;

float average;

average = (5 + 10 + 15 + 20) / 4;

printf("The number of seconds in an hour %dn",
seconds_in_an_hour);

printf("The average of 5, 10, 15, and 20 is %fn",
average);

printf("The number of seconds in 48 minutes is %dn",

return 1;
}

 

gcc编译运行输出结果

The number of seconds in an hour 3600
The average of 5, 10, 15, and 20 is 12.000000
The number of seconds in 48 minutes is 2880