Question

Can some one please help me

Answer 1

If we want to calculate the full prize we need to calculate how much the tax was:

420* 17$\frac{1}{2}$%=420*$\frac{175}{1000}$=420*$\frac{7}{40}$=21*$\frac{7}{2}$=73.5


so this is how much the tax was.

and the full prize is the cost of the ring and the tax: 420+73.5=493.5

so that's how much the buyer will pay