a)3
because it is ternery operator its work like a if.. else..
in the comdition part a=0 i.e. the result of expression is 
zero so it goes to else part i.s 3

b)b=3

c)b=2

in ternary operator a condition is required/// like..
<condition1>?<result1>:<result2>

b=(a=0)?2:3
so.. illegal use of ternary.../* "=" is an assignment operator*/

3 is the answer

2nd guy says we can't use "=" it's wroung we can use it in 
this condition .


expl:
 
1st it will check condition part , condition part will 
return false as, ANY VALUE OTHER THAN ZERO TAKEN AS TRUE IN 
C LANGUAGE ,   here we are assiging zero to 'a' which give 
false.


from basic of above contion , it condition return false it 
will execute or return 2nd statement, i.e 3

so out put will be 3

the value is 0 so this will go to 3.. the value of b=3
a) b=3... since we are not comparing the value os a's...
this is an assignment statement.... so a itself is 0, which
is an false condition.... so it moves to 3

b) the value of b=2... since -1 ia an non zero value... the
whole term wil become true....

c) b=2... same reson as above

actually the above conditional operater statement must be
full y enclosed witin braces.... then only we should assign
to a variable....

b=3
becoz in ternay operator if statement is true then it 
returns non zero vaqlue othervise it return 0 in that case 
we initialize the value of a is 0 therefore it will exicute 
a else part

a)1st answer will be              3
in statement 1
b)if a=0 replaced with -1         its an error
in statement 2
c)if a=0 replaced with -1          2

answer is 2 becoz -1 is taken as true in c language