Thread: selling price of computer

The selling price of a computer is $1760 excluding GST.
(a) Calculate the amount of GST (12½%) which needs to be added on.
(b) Calculate also the final selling price of the computer when GST is added on.
(c) What fraction is the GST of the final selling price?

I got
a) /8 x 1760 = $220
b) 1760 + 220 = $1980
c) 1/9 = 220

I agree.