Assume that when adults with smartphones are randomly selected, 51%use them in meetings or classes. If 7 adults smartphone users are randomly selected, find the probability that exactly 2 of them use their smartphones in meetings or classes.

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.

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