Money & Finance
Profit and Loss
Profit = Selling price β Cost price (when selling price > cost price) Loss = Cost price β Selling price (when cost price > selling price)
Profit percentage = (Profit / Cost price) Γ 100
Example: cost Β£40, sell Β£52: Profit = Β£12, profit% = (12/40) Γ 100 = 30%
Simple Interest
Interest earned on the original principal only:
I = PRT/100 or I = P Γ r Γ t
Where: P = principal, R = rate (%), T = time (years)
Β£500 at 4% for 3 years: I = 500 Γ 4 Γ 3 / 100 = Β£60
Compound Interest
Interest is added to the principal each period, so the next period earns interest on the new total:
A = P(1 + r/100)βΏ
Β£1,000 at 5% for 2 years: A = 1000 Γ 1.05Β² = 1000 Γ 1.1025 = Β£1,102.50
More than simple interest (which gives only Β£1,100) because interest earns interest.
VAT
Value Added Tax (VAT) is a tax added to the selling price of goods and services.
Price including 20% VAT: multiply by 1.20 Price excluding VAT: divide by 1.20
Budgeting
A budget is a plan for income and expenditure:
- Income β Expenditure = Surplus (positive) or Deficit (negative)
Sticking to a budget means spending does not exceed income.