Arithmatics

Arithmatics

1. Percentages

   • x% = X/100
   • x% of quantity = x/100 * quantity
   • 1 = 100/100
   • 0.1 = 10/100
   • 0.01 = 1/100

2. Profit and Loss

   • Profit = selling price - cost price
   • Loss = cost price - selling price
   • Marked up
     • Increase and and Profit
   • Marked down
     • Decrease and loss

3. Simple interest

   • I = simple interest
   • P = Principal or money borrowed
   • r = rate of interest per annum
   • n = time or duration
   • Formula = I = Prn

4. Reverse percentage

   • percent * unkown = money
     • percent/100 * unknown = value

5. Multipliers and chain percentages

   • One step method for increasing and decreasing quantities
   • 100% + 30%
     • 130%
       • multiplier = 1.30
   • Chain percentage - two or more percentage changes occur

6. Compound growth

   • Investment * (p.a. +100%) power of year