The table above shows the results of a survey of 100 voters who each responded "Favorable" or "Unfavorable" or "Not Sure" when asked about their impressions of Candidate M and Candidate N. What was the number of voters who responded "Favorable" for both candidates?
2 Explanations
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1
Tanvir Taher
Why is "Unsure" not taken into account for statement 1?
We only need to know how many voters were NOT Favorable for either candidate. Statement (1) tells us 40 were NOT favorable. That means 100 - 40 = 60 voters voted favorable for either M, N, or Both. We know that 40 were favorable for M and 30 for N.
40 + 30 = 70, which is 10 more than 60. So we know that exactly 10 voters must have voted for Both.
2 Explanations