I think the last output must be wrong.Can someone tell me who know about this?

Question

static void Main (string[]args)
{ int a = 12;
int b = ++a * 3;
int c = (b++)/4;
Console.WriteLine(a+" " +b+" "+c);
}
The output are :
13 40 9
Why the last output is 9
This's my calculation.
a = 12
b = 1+12 * 3 = 39
c = (39 + 1) / 4
= 40/4
= 10
So, the output will be 13 40 10
40/4 = 10, but why 9?
I know that the value of b doesn't stop at 39 and it incremented by 1(b++).That's why b is 40.

Answer 1

IN PREFIX ++a FIRST a IS INCREMENTED AND THAN EVALUATION TAKE PLACE.

IN POSTFIX b++ FIRST EVALUATION IS DONE AND THAN ITS VALUE IS INCREMENTED.

Answer 2

c = b++ / 4
//here b = 39 after this line b will get incremented ..
so c = 39 / 4 = 9
after this line b value will become 40

that's how post increment work
https://www.sololearn.com/discuss/489143/?ref=app