Percentages Percentage change v A percentage change can

Percentages.

Percentage change v. A percentage change can be either an increase or a decrease by a percentage

Increase Rf. 200 by 30% of 200 The amount after increase = 200 +60 = Rf. 260

Decrease 560 l by 45% of 560 The amount after decrease = 560 – 252 = 308 l

Calculating percentage increase or decrease (Profit or loss%) Profit = Selling price – Cost price ( P = S – C) Loss = Cost price – Selling price Percentage Profit/ Loss = (L=C–S)

Profit Percentage A car dealer buys an old car for $ 1000 and sells it for $1200. Calculate the percentage profit? Using the formula, % profit =

Loss Percentage A silver chain costing Rf. 180 is sold for Rf. 126. Find the percentage loss. Using the formula, % loss =

Finding cost price (before ) and selling price (after) By selling a watch for Rf. 252, a shopkeeper loses 16%. What is the cost price of the watch? Before(c) After (s) Amt % x 100 252 84

Finding cost price (before ) and selling price (after) A man bought some lemons for Rf. 30. He sold them at a profit of 20%. At what price did he sell them? Amt % Before(c) After (s) 30 100 x 120

Do the problems. 1. Increase 80 kg by 24% 2. Decrease 4500 by 20% 3. A damaged carpet which cost $180 when new is sold for $100. what is the percentage loss? 4. In 2008 the prison population was 1280. In 2010 It was increased by 25%. Calculate the population in the prison now? 5. Sana bought a book for $120 at a discount of 25% due to damage. What was the marked price of the book?

Simple and Compound Interest Simple interest With simple interest, the interest earned is not reinvested. This means that the amount of interest earned each year is unchanged. Compound interest With compound interest, the interest earned each year is reinvested. This means that the amount of interest earned each year increases.

Simple and Compound Interest Simple interest S. I = Simple Interest P = Principle amount ( invested amount) R = Rate of interest % (per annum) T = Time duration (years)

Simple and Compound Interest Find the interest Payable on $500 invested for 2 years at 6% per annum. S. I = ? P = 500 R = 6% T = 2 years

Simple and Compound Interest Find the rate in per cent per annum of simple interest if $1200 is the interest on $3000 invested for 4 years. S. I = 1200 P = 3000 R = %? T = 4 years

Simple and Compound Interest A = Total amount P = Principle amount ( invested amount) R = Rate of interest % (per annum) T = Time duration (years)

Simple and Compound Interest Meyga invests $500 in a bank at a rate of 3. 5% per year compound interest. Calculate the total amount of money she will receive at the end of 3 years. A = ? P = 500 R = 3. 5 % T = 3 years

Simple and Compound Interest Georg invests $5000 for 14 years at a rate of 2% per year compound interest. Calculate the interest he receives. Give your answer correct to the nearest dollar. A =? P = 5000 R = 2% T = 14 years C. I = ?

Solve each problem 1. Calculate the simple interest on $1200 for 3 years at 6% per annum. 2. Mia invests $7500 at 3. 5% per year simple interest. Calculate the total amount she has after 5 years. 3. Shameema invests $ 10800. After 4 years she has earned $3240 as simple interest. At what annual rate of interest did she invest her money. 4. Which is the better investment over ten years $20, 000 at 12% compound interest OR $ 30, 000 at 8% compound interest