Princeton_ I think its answer is wrong!!!

is fg + 2 prime?

(1) f is odd.

It give a huge variety of no. its uncertain...Note in Yes/No ques if its yes then sufficient if its no then also sufficient but if uncertain then insufficient..

Insufficient.

(2) g is even.

again gives a wide variety . Insufficient.

Now if we conclude 1 and 2
fg + 2

1+2+2 =5 Yes
5 +10+2=17 yes
21+20+2 =yes
11+2+2= 15 No

Two answers is definitely Insufficient..


IMO E

IMO E

Statement 1 is easy and not-sufficient

Statement 2: Consider 0 (even integer) and hence not-sufficient

So E

Hmm...where this one probably gets tricky in terms of solution is that:

Statement 1 is not sufficient. f could be 5 and g 1, and 5 + 2 is prime; or f could be 7 and g 1, and 7 + 2 is not.

Statement 2, as it's written, is NOT sufficient, but only because g could still be 0, and 0 + 2 is prime (2). For all other values of g (assuming that f is not also 0), fg + 2 is not prime.

So, as written, the correct answer should be E. But if they tweaked it to "f and g are POSITIVE integers" it would be B.