Answer:
[tex]\boxed{\dfrac{n}{s}}[/tex]
Step-by-step explanation:
[tex]\text{Number of buttons per shirt} = \dfrac{\text{Number of buttons}}{\text{Number of shirts}} = \mathbf{\dfrac{n}{s}}\\\\\text{There were $\boxed{\mathbf{\dfrac{n}{s}}}$ buttons on each shirt}[/tex]
