IMathAS-libretexts

Select all the relations which are not functions.

$\displaystyle {\left\lbrace{\left({x},{y}\right)}{\mid}{x}\right.}$ is the amount of sales tax on an item at the grocery store and $\displaystyle {y}$ is the purchase price of the item $\displaystyle {\rbrace}$
$\displaystyle {\left\lbrace{\left({x},{y}\right)}{\mid}{x}\right.}$ is the population of a town and $\displaystyle {y}$ is the number of law enforcment officers serving that town $\displaystyle {\rbrace}$
$\displaystyle {\left\lbrace{\left({x},{y}\right)}{\mid}{x}\right.}$ is an amount of alcohol consumed and $\displaystyle {y}$ is the blood alchohol concentration for a person consuming that amount of alcohol $\displaystyle {\rbrace}$
$\displaystyle {\left\lbrace{\left({x},{y}\right)}{\mid}{x}\right.}$ is the suggested retail price of particular car and $\displaystyle {y}$ is price paid by a random car buyer for that car $\displaystyle {\rbrace}$
$\displaystyle {\left\lbrace{\left({x},{y}\right)}{\mid}{x}\right.}$ is the price paid at checkout for one item and $\displaystyle {y}$ is the item purchased $\displaystyle {\rbrace}$