Answer:
If the total price of an object is A, and we have a tax of X%, then the new price of the object is:
Price = A + A*(X%/100%) = A*(1 + X%/100%)
In this case, the initial price of the car is:
A = $16,368
a) the tax is 6.6%
In this case, the price will be:
Price = $16.368*(1 + 6.6%/100%) = $17,448.288
b) the tax is 8.25%
In this case, the price will be:
Price = $16.368*(1 + 8.25%/100%) = $17,718.36
c) the tax is r.
we only replace X% by r.
Price = $16.368*(1 + r/100%)
d) We want to solve for r the above equation, we just need to isolate r.
Price/( $16.368) = (1 + r/100%)
Price/($16.368) - 1 = r/100%
(Price/($16.368) - 1)*100% = r