The table above shows the results of

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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Tanvir Taher

Why is "Unsure" not taken into account for statement 1?

May 27, 2015 • Comment

Jonathan , Magoosh Tutor

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.

Jun 15, 2015 • Reply

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Mike McGarry, Magoosh Tutor