Does the set of ordered pairs {(3, 11), (6, 1), (6, 4), (15, 4), (18, 18)} define a function?

He letter p on the number line below represents the number . (use the hyphen for negative numbers and write answer as a decimal, such as –7.2) number line from negative 7 to positive 7 in increments of 0.5 is shown. only the whole numbers are labeled. a point labeled p is placed at the eleventh tick mark to the left of 0.