codesnooker wrote:Answer should be (E).
1. f is odd. IN SUFFICIENT, as we don't have any information regarding g.
2. g is even. IN SUFFICIENT, as we don't have any information regarding f.
Lets take both statement together.
fg will be even. As odd X even = even.
Again fg + 2 = even integer (because even + even = even)
However fg + 2 = prime number only when fg = 0 (because 2 is the only even prime number and we have already prove that fg + 2 = even integer).
So any how we don't the value of fg, as it could be anything like -1, 0, 1, 2 etc. So again both (1) and (2) are INSUFFICIENT.
Hence IMO (E)
Hope this helps...
Nice explanation codesnooker! I agree with u. But if u take this approach -Taking both stmts in account, fg will be even and thus fg + 2 even.
Again as stmt-1and 2 are saying that f and g are odd and even integers, none of f anf g can be zero.
So fg + 2 can not be equal to 2 in any sense!
So fg + 2 will be even other than 2. So fg + 2 can not be prime. So taking both the stmts, we can conclude that fg + 2 can never be prime. So I can go for C.
- Can u pls point out where I am wrong?
