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Let us see some practical application on our daily life. We often notice banners, other displayed announcements in the market like discount 10%, save 20% or other offers of similar nature. One really needs a calculator to find difference of percentage between old and new prices displayed on displayed items/product. These examples may help us to have fairly good idea how these offers are really to our advantage.
A cell phone price tag is $250 along with a banner saying “save 20%” if you buy today. How to calculate discount price ?
Price tag- $250
20% of price= 250/100*20=$50
Our purchase price=$250-$50=$200
A DVD’s regular price is $25. The merchant offers 10% discount. How to calculate discount price?
Cost of DVD = $25
Discount (10%) = 25/100*10=$2.5
Purchase price would be = $25-$2.5=$22.5
A chocolate pack costs $10 and shop keeper offers 10% discount on purchase of two packs. What will average sale price of one chocolate pack ? How to calculate discount price?
Cost of one chocolate pack = $10
Cost of two chocolate pack = $10*2=$20
Discount (10%) on two packs= $20/100*10=$2
Discounted price of two chocolate packs=$20-$2=$18
Average price of one chocolate pack= $18/2=$9
In this article we have learnt how to calculate discount price by help of percentage calculation, percentage difference and calculate percentage difference. Remember percentage is a ratio that cannot always be added or difference of percentage be calculated in linear fashion because of its dependent factors i.e. portion, whole and 100 itself.
From this example we can understand behavior of percentage calculation with reference to change in quantity i.e. increase and decrease.
In general, a change of X percent in a quantity results in a final amount that is 100+X percent of the original amount (equivalently, 1+ 0.01 X times the original amount). This goes a bit farther and takes jumps towards understanding in terms of economics.
Weekly salary = $200
Increase (15%)= $200/100*15=$30
An employee would be entitled to draw $230 per week with increase of 15%.
Now see the decrease:
New weekly salary = $230
An employee would be entitled to draw $195.5 per week with decrease of 15%.