Successive Discount:
When two successive discounts on an article are m% and n% respectively given by shopkeeper. Then net discount is
Example 1
A shopkeeper has given two successive discounts of 20% and 10% on a certain article. Find the real discount?
Solution:
Let Marked Price is Rs. 100
Cost after 1st discount of 20%
= 100 – 20% of 100 Rs.
= 100 – 20 Rs.
= 80 Rs.
2nd discount is 10%
So, Cost after 2nd discount of 10%
= 80 – 10 % of 80 Rs.
= 80 – 8 Rs.
= 72 Rs.
Now using shortcut formula,
When the selling price of two articles are same but one of them sold at a Profit and another sold at a loss. For this case there will be always a net loss.
Example 2
Shopkeeper sells two watches each at RS. 100. The first one he sells at 10% profit and the other one he sells at 20% loss. Find the percentage profit or loss and Net amount of profit or loss?
Solution:
Total selling Price = 100 X 2 Rs = 200 Rs.
Cost price of 1st watch is
Cost Price of 2nd watch is
Here CP > SP so,
Now with the shortcut method,
Dishonest shopkeeper case:
If a shopkeeper sells his goods at a cost price but he uses false weight then.
Example 3
A dishonest shopkeeper sells goods at his cost price but uses a weight of 420 gm instead of 500 gm. Find his gain percent.
Solution:
When the selling price of articles is same as the cost price of y similar articles.
Example 4
If the cost price of 15 pencils is the same as the selling price of 12 pencils. Find the gain or loss percent?
Solution:
Cost price of 15 pencils = Selling price of 12 pencils
CP X 15 = SP X 12
Now SP > CP So, there will be profit.
Now assume CP = 4, then SP = 5
Example 5
If the cost price of 15 eggs is the same as the selling price of 20 eggs, what is the gain or loss percent?
Solution:
When a person recovers the cost price of x articles by selling y same articles (y < x) the profit percent =
For calculation always assume CP of an article as RS 1 or RS 100
Example 6
A seller selling 8 pencils gets the cost price of 10 oranges. What is the percentage profit?
Solution:
Alternative method
Assume CP of one pencil = Rs 1
CP of 8 pencils = Rs 8
SP of 8 Pencils = Cost price of 10 Pencils = 10 Rs.