Why I am getting both outputs?

Question

#include<stdio.h>

int main()
{
char a;
printf("Enter the subject");
scanf("%s",&a);

if(a= 'maths' )
{
printf("You won ₹10");
}
else if(a= 'science');
{
printf("You won ₹20");
}
else (a= 'science and maths');
{
printf("You won ₹45");
}
return 0;
}

Answer 1

#include<stdio.h>
#include<string.h>
int main()
{
char a[50];
printf("Enter the subject");
scanf("%s",a);

if(strcmp("maths",a)==0 )
{
printf("You won ₹10");
}
else if(strcmp("science",a)==0 )
{
printf("You won ₹20");
}
else
{
printf("You won ₹45");
}
return 0;
}