Sylvia had a case of 24 bottles and she sold x bottles.
The amount she ended up with is (24-x).
Sam had a case of 36 and sells 3x bottles (3 times as Sylvia).
Then, he ended up with (36-3x).
If they ended up with the same amount of bottles, then 24-x = 36-3x.
We can calculate x as:
![\begin{gathered} 24-x=36-3x \\ -x+3x=36-24 \\ 2x=12 \\ x=(12)/(2) \\ x=6 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/qzjugb4a0m91gasyskgoctxyqd9n5f87r5.png)
The number of bottles Sylvia sold is 6 bottles.