 Quandaries and Queries HI Question for you. If I have spent \$10.00, what is the mathamatical equation to figure out what the G.S.T (7%) was? Also if I were to spend \$80.00 on a hotel, and I would like to know how much G.S.T (7%) and how much provincial tax (6%) I spent how would I go about this. Nathan Hi Nathan, Think about going forward. If you bought something and the ticket price was, say \$60.00, then you have to add the 7% GST. So you have to pay \$60.00 plus 7% of \$60.00 But 7% of \$60.00 is 7/100 \$60.0 or 0.07 \$60.00, so you owe \$60.00 1.07 = \$62.40 Thus if you know the ticket price then you multiply by 1.07 to get the price including tax. Hence if you have the price including the GST then to get the ticket price you divide bt 1.07. That is  \$64.20/1.07 = \$60.00 Thus for your question, if the item including GST cost you \$10.00 then the cost, before tax, was  \$10.00/1.07 = \$9.35 For your second question, since the two taxes are both calculated on the cost before any tax you can add the taxes to get a total tax of 13%. Hence the price before tax was  \$80.00/1.13 = \$70.80 Penny Go to Math Central