3.
a. int a, int b; 
	There should not be a second "int" after the comma
b. int a = b;
   int b = 0;
	A cannot be assigned the value b before be is declared
c. int a = 0, b = 3.5;
	b is not an int
d. char grade = "A";
	'"A"' is a string not a char
e. char c = 1;
	1 is a numerical value not a char
f. int a, b, c, d, f;
	No error
g. char x = "This is a test.";
	'"This is a test."' is a string not a char