MATHS SALES TAX plse URGENT
posted by Anonymous on .
a shopkeeper buys an article at a discount of 15% on the printed price.
after charging a sales tax of 5% on the printed price, he sells the article at rs.630. find the profit

There are 3 things we must figure out in the this question.
1) What is the full price of this item + tax
2) What is the full price of this item
3) What is the price of this item with the 15% discount
4) Shopkeeper profit
For this whole problem let us assume that 'x' is equal to the full ticket price of the item:
1) rs. 630 (this is given to us in the question)
2) rs. 630 = 1.05(x)
rs. 630/1.05 = x
600 = x
Therefore the full ticket price of this item (with no tax) is rs. 600
3) price w/ 15% discount = 0.85(x)
 I got the 0.85 from 1.000.15 (if we're getting 15% off we are paying for 85% of the full price)
price w/ 15% discount = 0.85(600)
price w/ 15% discount = rs. 510
Therefore, the shopkeeper bought this item for rs. 510
4) Profit = Selling price  purchase price
Profit = 630510
Profit = rs. 120
Therefore the shopkeeper made a rs. 120 profit.