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तमिलनाडु बोर्ड ऑफ सेकेंडरी एज्युकेशनएसएसएलसी (अंग्रेजी माध्यम) कक्षा ८

The annual rate of growth in population of a town is 10%. If its present population is 26620, then the population 3 years ago was _________

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प्रश्न

The annual rate of growth in population of a town is 10%. If its present population is 26620, then the population 3 years ago was _________

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उत्तर

₹ 20,000

Explanation;

Hint:

Rate of growth of population r = 10%

Present population = 26620

Let population 3 years ago be x

∴ Applying the formula for population growth which is similar to compound interest,

26620 = `x(1 + "r"/100)^3`

∴ 26620 = `x(1 + 10/100)^3`

= `x(110/100)^3` 

∴ x = `26620 xx (100/110)^3`

= ₹ 20,000

The population 3 years ago was ₹ 20,000

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  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 4: Life Mathematics - Exercise 4.3 [पृष्ठ १३८]

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सामाचीर कलवी Mathematics [English] Class 8 TN Board
अध्याय 4 Life Mathematics
Exercise 4.3 | Q 1. (iii) | पृष्ठ १३८

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