Question

the population of a city increase each year 5%. what was its population in 1990if its population was 185220 in 1993

Answer 1

THANKS FOR THE QUESTION !

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ANS :

.......................... 1,60,000 ..........................

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GIVEN :

=> THE POPULATION OF A CITY INCREASES EVERY YR BY :

=> 5%

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CONDITION :

=> IN THE YR 1993 ,

=> POPULATION :

=> 1,85,220

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TO FIND :

=> POPULATION IN THE YR 1990

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LET,

=> THE POPULATION IN 1990 BE :

=> 1000 X

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THE GIVEN POPULATION IS OF THE YR 1993

=> SO,

=> PERIOD : ( N )

=> 1993 - 1990

=> 3 YRS

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FORMULA FOR COMPOUND INTEREST :

=> P ( 1 + R / 100 ) ^ N

=> 1000 X ( 1 + 5 / 100 ) ^ 3

=> 1000 X ( 105 / 100 ) ^ 3

=> 1000 X ( 21 / 20 ) ^ 3

=> 1000 X * 21 / 20 * 21 / 20 * 21 / 20

=> 50 X * 21 * 21 / 20 * 21 / 20

=> 5X * 21 * 21 * 21 / 40

=> X * 21 * 21 * 21 / 8

=> X * 9,261 / 8

=> X * 1157.625

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BUT THE AMOUNT IS GIVEN :

=> 1,85,220

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1,85,220 = X * 1157.625

=> X = 1,85,220 / 1,157.625

=> X = 160

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POPULATION IN THE YEAR 1990 :

=> 1000X

=> 1000 * X

=> 1000 * 160

=> 1,60,000

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HOPE IT WILL HELP U ......

THANKS AGAIN......

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