Simple Interest and Compound Interest

The principal is £200, and the annual interest is $200\times 4\%=\pounds 8$. For 5 years, multiply the yearly interest by the number of years: $\pounds 8\times 5=\pounds 40$.

The principal is £300, and the interest for 1 year is $\pounds 300\times 4\%=\pounds 12$. For 3 years, multiply the 1-year interest by 3: $\pounds 12\times 3=\pounds 36$.

Compound interest means the total amount after 2 years is calculated as $\pounds 500\times (1+5\%{)}^2$. First year: $\pounds 500\times 1.05=\pounds 525$. Second year: $\pounds 525\times 1.05=\pounds 551.25$.

The interest for 1 year is $\pounds 1000\times 5\%=\pounds 50$. For 4 years, multiply the 1-year interest by 4: $\pounds 50\times 4=\pounds 200$. Add the interest to the principal: $\pounds 1000+\pounds 200=\pounds 1200$.

The principal is £500, and the annual interest is $\pounds 500\times 6\%=\pounds 30$. For 4 years, multiply the 1-year interest by 4: $\pounds 30\times 4=\pounds 120$. Add the interest to the principal: $\pounds 500+\pounds 120=\pounds 620$.

Use the compound interest formula: Total Amount = Principal $\times (1+\text{Interest Rate}{)}^n$. After 1 year: $\pounds 200\times 1.05=\pounds 210$. After 2 years: $\pounds 210\times 1.05=\pounds 220.5$.