Mrs Lim bought a blender at 20% discount during a sale. She paid $90.72 including 8% GST. What is the original price of the blender? Ans: $ ___

1. Find the discounted price before GST was added.

Let the discounted price be $100\%$.
The price including $8\%$ GST is $108\%$.
Discounted price $= \frac{90.72}{1.08} = \char36{}84$

2. Find the original price before the discount.

Let the original price be $100\%$.
The discounted price is $100\% - 20\% = 80\%$.
Original price $= \frac{84}{0.80} = \char36{}105$