Mathematics discountage

Question

At a Great Singapore Sale, Jennifer bought a handbag which was on a 30% discount off its original price. She paid $674.10 which was inclusive of a 7% GST on the discounted price. What was the original price of the handbag?

Answer 1

OP = original price

DP = discounted price

 

From the 1st sentence, we have:

DP = OP - 0.3 (OP) = 0.7 (OP)

 

From the second sentence:

DP + 0.07 (DP) = 674.10

 

Simplify:

1.07 (DP) = 674.10

 

Now, substitute for DP using the 1st equation:

(0.7)(1.07) OP = 674.10

0.749 OP = 674.10

 

OP = 900