Which statement below best explains the credit terms for $3/15,$ n$/45?$

The buyer will receive a $15$ percent discount if it pays within $3$ days.

The buyer will receive a $15$ percent discount if it pays within $45$ days.

The buyer will receive a $3$ percent discount if it pays within $15$ days.

The buyer will receive a $3$ percent discount if it pays within $45$ days.