Question

State, whether the following relations are functions{ {2, 3), (2, 4), (2, 5), (2, 6), (2, 7) }. Write 1 if they are a function and 0 if they are not

Answer 1

A function is a set of ordered pairs in which each $x$-element has only ONE $y$-element associated with it.
As $2$ is associated with $y-$ coordinates of the ordered pairs, the given relation is not a function.