Posted by joi on Saturday, October 29, 2011 at 7:05am.
1.Mr Sim bought new tv at a discounted price of 15%.He paid $836, inclusive of 3% GST(goods and services tax. What was the original price of the tv?
2.How to calculate original price before GST and before discount? What is the formula? Tks

Maths urgent help needed,  Damon, Saturday, October 29, 2011 at 8:11am
original price = p
discounted price = 0.85 p
tax = .03(.85 p) = .0255 p
so
836 = .85 p + .0255 p = .8755 p
p = 954.88
check
.85 * 954.88 = 811.65
811.65*1.03 = 836 good