a) Cody has just bought a gift in Nunavut and paid $474.97.

What exactly was the retail price before taxes?

Note that Nunavut charges GST of 5%

b) Siran has just bought a gift in Prince Edward Island and paid $502.14.

What exactly was the retail price before taxes?

Note that Prince Edward Island charges GST of 5% and PST of 10% (and P.S.T is charged on top of G.S.T).

Any help?