मराठी

The Population of a Town Decreased by 12% During 1998 and Then Increased by 8% During 1999. Find the Population of the Town, at the Beginning of 1998, If at the End of 1999 - Mathematics

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प्रश्न

The population of a town decreased by 12% during 1998 and then increased by 8% during 1999. Find the population of the town, at the beginning of 1998, if at the end of 1999 its population was 2,85,120.

बेरीज
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उत्तर

Let the population in the beginning of 1998 = P
The population at the end of 1999 = 2,85,120(A)
r1 = - 12% and r2 = + 8%

∴ A = P`( 1 - r_1/100 )( 1 + r_2/100 )`

⇒ 2,85,120 = P`( 1 - 12/100 )( 1 + 8/100 )`

⇒ 2,85,120 = P`( 22/25 )( 27/25 )`

⇒ P = `[ 2,85,120 xx 25 xx 25 ]/[ 22 xx 27 ]` = 3,00,000. 

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Concept of Compound Interest - When the Time is Not an Exact Number of Years and the Interest is Compounded Yearly
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 3: Compound Interest (Using Formula) - Exercise 3 (D) [पृष्ठ ५३]

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सेलिना Concise Mathematics [English] Class 9 ICSE
पाठ 3 Compound Interest (Using Formula)
Exercise 3 (D) | Q 4 | पृष्ठ ५३

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