Basic C programming explanations?

[zaihed13]

Hello I had some questions for a quiz that I got wrong cause I was confused on them. Would anyone please be kind enough to tell me why each code outputs what it does?

1.

int a=13, b=5;
if (3 < a < 10) 
printf("A");
b = 2*a; 
printf("%d", b);

shouldn't this just output 26 since 13 isn't less than 10?

2.

int a=8;
if (a = 5) { 
printf("A"); 
} 
else 
printf("B"); 
printf("%d", a);

shouldn't this just output B due to 8 not being equal to 5?
3.

int a=3, b=8;
if (a > 3)  
if (b < 5)  
printf("A"); 
else  
printf("B"); 
printf("C");

why doesn't this output both b and c?

[SirPrattlepod]

int a=13, b=5;
if (3 < a < 10) 
printf("A");
b = 2*a; 
printf("%d", b);

the expression 3 < a < 10 is equivalent to (3 < a) < 10 and therefore if a is 13, then (3 < 13) < 10 ==> 1 < 10 ==> 1 (true) so the if statement true. The output would be A26

int a=8;
if (a = 5) { 
printf("A"); 
} 
else 
printf("B"); 
printf("%d", a);

Consider:

if (a = 5) { // This is assigning 5 to a, and similar to the previous explanation if(5) evaluates to true so the output would be

A5

int a=3, b=8;
if (a > 3)  
if (b < 5)  
printf("A"); 
else  
printf("B"); 
printf("C");

fixing indentation:

int a=3, b=8;
if (a > 3)  
    if (b < 5)  
        printf("A"); 
    else  
       printf("B"); 
printf("C");

Now it can clearly be seen that only "C" will be printed because the first conditional is false