Percentage increase/decrease
These examples gives the idea, how to solve the change in calculations including percentages. The formula used is exactly the same as in previous topic but a, b and/or p may need some calculations before the value is known.
Example 1.
Original price of a product is 380 euros. If it is raised by 15 %, what is the new price?
The original value a = 380 euros, p = 0.15 and b needs to be solved.
The new price will be the original price plus the raise, so the new price is 380 euros + 57 euros = 437 euros.
Example 2.
The value of a share decreased from 20 euros to 5 euros. How much is it in percentages?
Method 1:
The difference in value is 20 euros - 5 euros = 15 euros.
Now, b = 15 euros and a = 20 euros. Thus
Method 2:
One way of solving this, is to solve how many per cents the new value is from the original and check how much does it deviate from 100%.
.
The minus-sign tells us, that the value decreased. Thus, the value of the share decreased by 75%.
Example 3.
The cost of cleaning changed from 150 euros to 225 euros. How much is the changes in per cents?
The basic value is the original value before the change.
Method 1:
The difference is 225 euros - 150 euros = 75 euros.
.
Method 2: