Answer:
Marked down amount = $11.25
Sales tax amount = $1.31
Explanation:
The initial amount Andrew bought the book was $30.
If the book was later marked down by 37.5%, therefore the marked down will be;
![(37.5)/(100) * 30 = 0.375 * 30 = 11.25](https://img.qammunity.org/2022/formulas/mathematics/high-school/r3xl641wp3hqppxh5ra4z1f2yq526jv1ry.png)
The marked down price will be;
![30 - 11.25 = 18.75](https://img.qammunity.org/2022/formulas/mathematics/high-school/65zu3i9glqyqa3ae805ldo48pvpkfoyh6p.png)
If the sales tax rate was 7%, the sales tax amount will be;
![(7)/(100) * 18.75 = 1.31](https://img.qammunity.org/2022/formulas/mathematics/high-school/k3l2w9rqn40835vcttjn2qg6213uwvsjwx.png)