## Tutorial

##### 'What percentage of' Calculation

This calculation solves - **What is 15 percent of 100?.** This is a basic percentage calculation and expressed in terms of a 15/100 ratio. This is done by multiplying by 100.
The Formula is - **(15/100)*100 = 15.**

##### 'What number is a percentage of' Calculation

This calculation solves – **339 is what percent of 1000?.** This calculation is very near to the first one however this gives the percentage value for 339 of 1000.
The Formula is - **(339*100)/1000 = 33.90.**

##### 'Increase from or Decrease from' Calculation

This calculation solves – **Increase from 0.30 to 10000?.** Seems this calculation is different from above two however, this is still same as we write the formula as ratio of two numbers.
The Formula is - **((10000-0.30)/0.10)*100 = 3333233.33**

##### Multiplication by a percentage

This calculation solves – **100 multiplied by 45%?.** Its a basic calculation and as simple as writing 34% as a ratio of 34/100.
The Formula is - **(100*45)/100 = 45**

##### Division by a Percentage

This calculation solves – **43 divided by 85?.** Unlike multiplication by a percentage calculation and another time involves writing a percentage as a ratio with 100 as the denominator.
The Formula is - **43/(85/100) = 50.59**

##### Increase by a Percentage

This calculation solves – **Increase 70000 by 9.5%?.** This one same as multiplication by a percentage calculation as shown above but the only dissimilarity is that we simply add the number we are multiplying by.
The Formula is – **70000*(1+(9.5/100)) = 76650**

##### Decrease by a Percentage

This calculation solves – **Decrease 70000 by 9.5%?.** Unlike "increase by a percentage" calculation as given above now its doing subtract instead of add.
The Formula is – **70000-(70000*(9.5/100)) = 63350**