1. Resources Financial Maths $20000 % Problems to Solve Simple Percentage Percent with fractions and decimalsPercent with fractions and decimals % Increase % Decrease Markup and Discount Simple Interest Compound Interest

2. Solve these simple percentages. (1)Find 10% of $20 (2)Find 50% of $100 (3)Find 30% of $60 (4)Find 70% of $120 (5)Find 75% of $200 Think! split the amount into 1% (by dividing by 100); then multiply by the number of % you need! 2) 50% of $100 = 0.5 × 100 = $50 3) 30% of $60 = 0.3 × 60 = $18 4) 70% of $120 = 0.7 × 120 = $84 5) 75% of $200 = 0.75 × 200 = $150 1) 10% of $20 = 0.1 × 20 = $2 Solutions Working

3. Other percentage problems. (1)Find 35% of $120 (2)Find 8% of 250g (3)Find 12.5% of 60mL (4)Find 17½% of 70 km (5)Find 2.4% of $65.50 2) 8% of 250g = 0.08 × 250 = 20g 3) 12.5% of 60mL = 0.125 × 60 = 7.5mL 4) 17½% of 70km = 0.175 × 70 = 12.25km 5) 2.4% of $65.50 = 0.024 × 65.50 = $1.57 1) 35% of $120 = 0.35 × 120 = $42 Think! split the amount into 1% (by dividing by 100); then multiply by the number of % you need! Solutions Working

4. Find these percentage increases. (1)Increase $100 by 15% (2)Increase 85kg by 12½% (3)Increase 754m by 6.8% Think! split the amount into 1% (by dividing by 100); then multiply by 100% PLUS % you increase! 1)Increase $100 by 15% 100% + 15% = 115% 115% of $100 = 1.15 × $100 = $115 2) Increase 85kg by 12½% 100% + 12½% = 112½% 112½% of 85kg = 1.125 × 85kg = 95.625kg 3) Increase 754m by 6.8% 100% + 6.8% = 106.8% 106.8% of 754m = 1.068 × 754m = 805.272m Solutions

5. Find these percentage decreases. 1) Decrease $100 by 75% 2) Decrease 65km by 34.8% 3) Decrease 375mL by 7½% 1)Decrease $100 by 75% 100% - 75% = 25% 25% of $100 = 0.25 × $100 = $25 2) Decrease 65km by 34.8% 100% - 34.8% = 65.2% 65.2% of 65km = 0.652 × 65km = 42.38km 3) Decrease 375mL by 7½% 100% - 7½% = 92½% 92½% of 375mL = 0.925 × 375mL = 347mL Think! split the amount into 1% (by dividing by 100); then multiply by 100% PLUS % you increase!

6. Solutions 2) The selling price of a computer is the cost price plus Mark-up 30% plus GST at 10%. The cost price of a computer is $650. Work out the selling price of the computer. Practical Problems 1) Work out 40% off a $530.00 electrical appliance. (3) Cory sees three different advertisements for jeans. (a) Rip Curl – 15% off $130 (b) Quicksilver – ⅓ off $160 (c) Billabong – $105 + 10% GST Work out the cost of the jeans in each advertisement. Mark-up price = CP + 30% = $650 × 1.3 = $845 Sell Price = Mark-up  1.1 = $845 × 1.1 = $929.50 (a) 15% off $130 = 0.85  $130 = $110.50 (b) ⅓ off $160 = ⅔  $160 = $106.67 (c) $105 + GST = $105  1.1 = $115.50 40% off $530.00 = 0.6 × $530 = $318

7. Find the simple interest for the following: (1)$60 for 2 years at 4% interest per annum (2)$150 for 3 years at 7.5% interest p.a. (3)$5000 for 6 years at 3¾% p.a. (4)$2500 for 48 months at 12.5% p.a. (5)$750 for 32 months at 6.5% p.a. Find the interest% for one year then multiply by the number of years! 1) SI = PRT = 60 × 0.04 × 2 = $4.80 2) SI = PRT = 150 × 0.075 × 3 = $33.75 3) SI = PRT = 5000 × 0.0375 × 6 = $1125 4) SI = PRT = 2500 × 0.125 × 48 ÷ 12 = $1125 5) SI = PRT = 750 × 0.065 × 32 ÷ 12 = $130

8. Find the compound interest for the following: (1)$150 for 2 years at 7% p.a. (2)$500 for 3 years at 12% p.a. (3)$7500 for 3 years at 6.5% p.a. (4)$35000 for 7 years at 10% p.a. (5)$250 000 for 25 years at 7.5% p.a. 1)CI = P (1 + %) terms = $150  (1.07) 2 = $171.34 Compounding formula P (1 + %) terms 2) CI = P (1 + %) terms = $500  (1.12) 3 = $702.46 3) CI = P (1 + %) terms = $7500  (1.065) 3 = $9059.62 4) CI = P (1 + %) terms = $35000  (1.1) 7 = $68205.10 5) CI = P (1 + %) terms = $250000  (1.075) 25 = $1 524 584.90