The population of a town is 7,000. If the percentage increase in the male and female population is 11% and 8% respectively, the new population will be 7,680. Find the number of female citizens in the town
एक कस्बे की जनसंख्या 7,000 है। यदि पुरुष और महिला जनसंख्या में प्रतिशत वृद्धि क्रमशः 11% और 8% है, तो नई जनसंख्या 7,680 होगी। कस्बे में महिला नागरिकों की संख्या ज्ञात कीजिए।
Detailed Solution & Logic
Let number of males = x, number of females = 7000 - x
New male population = $ x + 11% \text{ of } x = x (1 + \frac{11}{100}) = \frac{111}{100}x $
$ New female population = (7000 - x) + 8% \{ of } (7000 - x) = (7000 - x)\left(1 + \frac{8}{100}\right) = \frac{108}{100} (7000 - x) $
Total new population = 7680
$ \frac{111}{100}x + \frac{108}{100} (7000 - x) = 7680 $
$ 111x + 108(7000 - x) = 768000 $
$ 111x + 756000 - 108x = 768000 $
$ 3x = 12000 $
$ x = 4000 $
Number of females = 7000 - 4000 = 3000
Answer: 3000