Question

Which of the following sets is a function?

{(17, -8), (1, 16), (53, 9), (1, 23)}
{(0, 1), (-2, 8), (5, 19), (2, 8)}
{(1, 0), (11, 0), (-5, 7), (1, 9)}

Answer 1

Answer: {(0,1), (-2, 8), (5,19), (2, 8)}

Explanation:
The other two sets have two different y values for one x value. So it has to be the set in the middle.