IMO Ans should be A

N- Not sure, F – Favorable, U – unfavorable
Candidate M –> F = 40, U = 20, N = 40
Candidate N -> F = 30, U = 35, N = 35

Stmt 1 -> U+ N has 40 common people for both candidates
40 out of 60 (for cand M) also voted as U+N for cand N. So remaining 20 must have voted favorable for cand N.
Now, cand N has 30 fav votes. So 10 out of 40 (cand M) would have voted as favorable for cand N.

Conclusion, 10 people always voted favorable for both candidates. SUFF

Stmt 2 -> 10 common people for U for both candidates.
So, 10 out of 20 (cand M) would have voted either F or N for cand N. Now, all 40 (who voted F for cand M) can vote U or N for cand M OR some of them can vote as F for cand M. Stmt 2 does not give much detail. NOT SUFF

Let me know what’s the OA

We can solve this only if we know the nos of people who voted favourable for either M or N, Now

Stmt 1 says that

" the nos of voters who did not respond favorable for either candidate is 40"

F -- Favorable, U -- Unfavorable NS -- Not sure
This can be rephrased as
40 voters did not respond F for either M or N or both

(i.e. if a voter responded NS for both, U for both or NS for one and U for the other he has responded not F for either of the candidates)
this means that some of them could have responded F for M, U or NS for N or vicerversa and voters who responded U,NS for both.

Now to find the nos of people who responded F for either candidate we need the nos of voters who responded U or NS for both the candidates, i.e excluding this set of voters all others responded F for at least M or N.

Hence this data is INSUFFICIENT to answer the Q

Stnmt 2: says that 10 voters responded Unfavourable for both but we still need the nos of voters who responed Not Sure for both, NS for 1 and U for other to get the nos of votesrs who responded F for either of the candidates hence NOT SUFF

Now we combine both we still have cannot extract the exact nos of voters who responded NS for both, U for both and U for one, N for other.

Hence IN SUFF

so according to me ans should be E

Thank you the answer is A.

Thanks for the answer,
I was also stuck between A & E, I think I interpreted the first statement a little too much assuming that it would include voters who had not responded favorable for both candidates, however If A is correct then kajcha's explation for A is correct but according to me then stmt 1 would mean that:

40 voters did not respond favorable for either M or N but not both, i.e they responded favorable for 1 and Unfavorable or Not sure for other.

we can only interpret 40 as U + N if the stsmt mentioned " for both candidates" instead of "either candidiate"

then this 40 can also be said as the nos of people who responded favorable for either one, which is the data we require

hence Fvaorable for both = 40 + 30 -40 =30 people so SUFF

please review this and correct me if I'm wrong
so ans must me A