Question

population of town was 150000 three years ago. it increased by 2% 5% and 8% in last 3 years .what is the present population of the town?​

Answer 1

Answer:

⠀⠀⠀⌬ Population 3 years ago = 150000

⠀⠀⠀⌬ Increased by 2%, 5% and 8%

⠀⠀⠀⌬ Present population of town?

$\underline{\bigstar\:\textsf{According to the given Question :}}$

$:\implies\sf Present=Old \times (100+Inc.)\% \times (100+Inc.)\% \times (100+Inc.)\%\\\\\\:\implies\sf Present=150000\times (100+2)\% \times (100+5)\% \times (100+8)\%\\\\\\:\implies\sf Present = 150000 \times 102\% \times 105\% \times 108\%\\\\\\:\implies\sf Present = 150000 \times \dfrac{102}{100} \times \dfrac{105}{100} \times \dfrac{108}{100}\\\\\\:\implies\sf Present = 15 \times102 \times105 \times 1.08\\\\\\:\implies\sf Present = 2016 \times 102\\\\\\:\implies\sf Present = 205632$

⠀

$\therefore\:\underline{\textsf{Hence, present population of the town is \textbf{2,05,632}}}.$

$\rule{200}{1}$

$\boxed{\begin{minipage}{7 cm}\underline{\text{Some Important Formulae Related to it :}}\\ \\\sf Increase = Old Population\times(100+\sf Increase)\%\\ \\Decrease=Old \:Population\times(100-Decrease\%)\end{minipage}}$