Brandon buys a radio for 49.99 in a state where the sales tax is 7%?

Please this question really gets me Cant figure it out thanks!

1 Answer
Dec 11, 2017

You do not state if the 49.99 is before or after tax.I have given you the answer to both. Have a look at how I worked it out.

Explanation:

Assumtion: the 49.99 is before tax and you need the final cost.

#49.99 + (7/100xx49.99)#
#49.99+ 3.4993#
#53.4893#
Round this to 2 decimal places.
#53.49#
~~~~~~~~~~~~~~~~~~~~~~~~
Assumption: the 49.99 is after tax and you need the price

Set the unknown original price as #x# then we have:

100% of #x# + 7% of #x# is the same as 107% of #x#

Write as #107/100x=49.99#

If you multiply both sides by #100/107# then it changes the #107/100# on the left side into 1 giving:

#1xx x=49.99xx100/107#
#x=46.7196....#
Where the dots mean the numbers go on for a long time.

Rounding this to 2 decimal places gives:
46.72