ANSWER:
The total cost of the skate board is $74.61.
SOLUTION:
Given, Luis wants to buy a skateboard that usually sells for $79.99. all merchandise is discounted by 12%. luis has to pay a state sales tax of 6.75%.
We need to find what is the total cost of the skateboard.
Final cost is nothing but original amount subtracted by discount and added with tax.
final cost = original cost – discount + sales tax
Original cost = $79.99
Discount = 12% of original cost
![\begin{array}{l}{=12 \% * 79.99} \\\\ {=(12)/(100) * 79.99} \\\\ {=(959.88)/(100)} \\\\ {=9.5988}\end{array}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/xfurujjouxpon860ztptnw1ms2l0uohyvl.png)
discount is $9.6 approximately
Sales tax = 6% of cost after discounting
![\begin{array}{l}{=6 \% * \text { (original cost - discount) }} \\\\ {=(6)/(100) *(79.99-9.6)} \\\\ {=(6)/(100) *(70.39)} \\\\ {=(422.34)/(100)} \\\\ {=4.2234}\end{array}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/khtgzk6rbz1qunqcxp6clxcn1eoqr50h2q.png)
Sales tax is $4.22 approximately
Now, final cost = 79.99 – 9.6 + 4.22
= 84.21 - 9.6
= 74.61
Hence, the total cost of the skate board is $74.61