if a computer costs $600.00 and the sales tax rate is 7.5 percent, what is the total cost of the computer…

if a computer costs $600.00 and the sales tax rate is 7.5 percent, what is the total cost of the computer? $607.50 $615.00 $622.50 $645.00
Answer
Explanation:
Step1: Calculate sales tax amount
The sales - tax amount is calculated by multiplying the cost of the computer by the sales - tax rate. The sales - tax rate is $7.5%=0.075$, and the cost of the computer is $C = 600$. So the sales - tax amount $T$ is $T=600\times0.075$. $T = 600\times0.075=45$
Step2: Calculate total cost
The total cost $TC$ of the computer is the sum of the cost of the computer and the sales - tax amount. So $TC = 600+T$. $TC=600 + 45=645$
Answer:
$645.00$ (corresponding to the last option)