Expert: Robi Bhattacharjee - 3/22/2009

Question
1. if the price of gasoline increase by 25% and Ron intends to spend only 15% more on gasoline, by what % should he reduce the quantity of petrol that he buys?
2. A merchant who marked his goods up by 50% subsequently offered a discount of 2%. What is the percentage profit that the merchant make after offering the discount?
3. by selling an article at 80% of its marked price, a merchant make a loss of 12%. What will be the % profit made by the merchant if he sells the article at 95% of its marked price?

Answer
Hi Cathie,


1. Well, if the price goes up by 25%, Ron will have to pay 125/100 times as much as usual or rather 5/4 times as much. However, he only wants to pay 15% more or 115/100 = 23/20 times as much. So in order to pay this much, he will have to buy

23/20/(5/4) times as much as usual which = 23/20*4/5 = 23/25 times as much as he usually buys. So that is 92% of his normal quantity or 8% less.

2. Well, increasing by 50% means you are selling it for 3/2 the price. Marking it down 2% means you are selling it for 98/100 the price you were originally selling it. So 3/2*98/100 = 147/100. So if you sell it for 147/100 of the price, you are selling it at 147% so you are making a 47% profit.

3. Making a loss of 12% is the same thing as selling it for 88% of the original price. So if 80% yields 88% of the original price, 95% must yield 95*88/80 % = 104.5%. So you make a 4.5% profit.



I hope this helped,
Robi