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Percentage Lesson Part 5 Population Problems

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Population Population appreciation or depreciation follows Compound interest pattern. Compound interest pattern means when percent increase or decrease always calculated on current value. Formula Appreciation Formula r t Let present population of certain city P Rate of appreciation (Growth rate)-1% Population after t years = Pt Pt = Po(1+100) o Depreciation Formula Let present population of certain city = Po Rate of depreciation (Decrease rate)-1% Population after t years P r t Pt- Pt = Po (1-100 P0 |

Population growth using Multiplication Factor Population of a city increase at the rate of 10%. If we use formula for this than the value of population after (let) 3 years would be 3 10 100 100 + 103 Step 1 P3 = Po I-100 Step -2 3 110 100 P3-Po Step-3 P3 = Po(1.1)3 Step-4 Here 1.1 is multiplication factor

Population growth using Multiplication Factor Population of a city increase at the rate of 10%. If we use formula for this than the value of population after (let) 3 years would be 3 10 100 100 + 103 Always use Multiplication Factor For solving question like this Step -1 P3 = Poll+ Ps= Po( 100 Ps = Po (100 P3 = Po(1.1)3 Calculation of Multiplication Factor (M.F Population increase Add 100 to rate and put two decimal from Right hand side If rate is 15 % then Mf. = 100 15 = 115 = 1.15 Population decrease Subtract 100 to rate and put two decimal from Right hand side If rate is 12 % then M.F = 100-12 = 88 = 0.88 Step -2 3 3 110 Step-3 3 Step-4 Here 1.1 is multiplication factor

Population increase and decrease Application If the annual increase in the population be 15% and present population be 20,000. What will be the population after 2 years a. 28800 b. 26450 c. 25088 d. 24200

If the annual increase in the population be 15% and present population be 20,000. What will be the population after 2 years a. 28800 b. 26450 c. 25088 d. 24200 por,Jahon o 2Xa.s Po r mg ,. MA2

The population of a city in the first two year increase by 20% and in the next year decrease by 15%. If current population be 25000 then the population after 3 years a. 28800 b. 29700 c. 30600 d. 18400

The population of a city in the first two year increase by 20% and in the next year decrease by 15%. If current population be 25000 then the population after 3 years a. 28800 b. 29700 c. 30600 d. 18400

The annual production in cement industry is subject to business cycles. The production increases for two consecutive years consistently by 18% and decreases by 12% in the third year. Again in the next two years, it increases by 18% each year and decreases by 12% in the third year. Taking 2008 as the base year, what will be the approximate effect on cement production in 2012? a. 24% increase c.45% increase [IIFT (2012)] b.37% decrease d. 60% decrease